From e120dc260f4c338360944fb7b54fb108c4487366 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Sun, 20 Sep 2026 23:34:24 +0300 Subject: [PATCH 01/31] Added and changed constants. --- src/part1/constants.py | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..a01b7b98 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -15,24 +15,23 @@ from typing import Final -# TODO: замените заглушки (0) на корректные значения, см. TASK.md. -# Все константы, зависящие от ёмкостей *_BITS, должны вычисляться из них. + # Twitter's original Snowflake epoch: 2010-11-04 01:42:54.657 UTC. -EPOCH_MS_DEFAULT: Final[int] = 0 +EPOCH_MS_DEFAULT: Final[int] = 1288834974657 # Node identifier used when the caller does not supply one. -NODE_ID_DEFAULT: Final[int] = 0 +NODE_ID_DEFAULT: Final[int] = 1 # Width of each field, in bits. -TIMESTAMP_BITS: Final[int] = 0 -NODE_ID_BITS: Final[int] = 0 -SEQUENCE_ID_BITS: Final[int] = 0 +TIMESTAMP_BITS: Final[int] = 41 +NODE_ID_BITS: Final[int] = 10 +SEQUENCE_ID_BITS: Final[int] = 12 # Largest value each field can hold. -TIMESTAMP_MS_MAX: Final[int] = 0 -NODE_ID_MAX: Final[int] = 0 -SEQUENCE_ID_MAX: Final[int] = 0 +TIMESTAMP_MS_MAX: Final[int] = 2 ** TIMESTAMP_BITS - 1 +NODE_ID_MAX: Final[int] = 2 ** NODE_ID_BITS - 1 +SEQUENCE_ID_MAX: Final[int] = 2 ** SEQUENCE_ID_BITS - 1 # Здесь можно добавить собственные вспомогательные константы # (например, сдвиги полей при сборке идентификатора). From 0aebe01c8b4a70035f7f2f09135a84fb68718728 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Sun, 20 Sep 2026 23:44:07 +0300 Subject: [PATCH 02/31] Added function 'read_current_millis' --- src/part1/snowflake.py | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index d3abf050..81bed18d 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -25,17 +25,10 @@ def read_current_millis(epoch_ms: int) -> int: - """Read the number of milliseconds elapsed since the custom epoch. + current_time = int(time.time() * 1000) - Args: - epoch_ms: The custom epoch expressed as Unix milliseconds. - Returns: - The count of whole milliseconds between ``epoch_ms`` and now. May be - negative if ``epoch_ms`` lies in the future. - """ - # TODO: реализуйте функцию - return 0 + return current_time - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: From 5ce5d0d5f6c288b905c4afd6f45efffd0c70ceef Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Mon, 21 Sep 2026 15:05:42 +0300 Subject: [PATCH 03/31] modifided 'decode_timestamp_ms' --- src/part1/snowflake.py | 23 ++--------------------- 1 file changed, 2 insertions(+), 21 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 81bed18d..2b2e3f18 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -32,32 +32,13 @@ def read_current_millis(epoch_ms: int) -> int: def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: - """Read the timestamp field out of a Snowflake identifier. + default_time = snowflake_id >> 22 - Args: - snowflake_id: An identifier produced against the same epoch. - epoch_ms: The epoch the identifier was generated against. Defaults to - the original Twitter epoch (2010-11-04 01:42:54.657 UTC). - Returns: - The absolute Unix time in milliseconds at which the identifier was - generated. - """ - # TODO: реализуйте функцию - return 0 + return default_time + epoch_ms def decode_node_id(snowflake_id: int) -> int: - """Read the node identifier field out of a Snowflake identifier. - - Args: - snowflake_id: An identifier produced by :func:`generate_snowflake_id`. - - Returns: - The node identifier packed into ``snowflake_id``, in the range - ``[0, NODE_ID_MAX]``. - """ - # TODO: реализуйте функцию return 0 From 2de06967bd4a7fa29568b2d34475569100661f2e Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Mon, 21 Sep 2026 15:10:30 +0300 Subject: [PATCH 04/31] modificed 'decode_node_id' --- src/part1/snowflake.py | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 2b2e3f18..9798a340 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -39,7 +39,9 @@ def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> def decode_node_id(snowflake_id: int) -> int: - return 0 + node_id = (snowflake_id >> 12) & 0b1111111111 + + return node_id def decode_sequence_id(snowflake_id: int) -> int: From b1f51c48c003d628162ba24a1ad2af6706686849 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Mon, 21 Sep 2026 15:12:49 +0300 Subject: [PATCH 05/31] modificed 'decode_sequence_id' --- src/part1/snowflake.py | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 9798a340..4d6217af 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -45,17 +45,9 @@ def decode_node_id(snowflake_id: int) -> int: def decode_sequence_id(snowflake_id: int) -> int: - """Read the sequence counter field out of a Snowflake identifier. + sequence_id = snowflake_id & 0b111111111111 - Args: - snowflake_id: An identifier produced by :func:`generate_snowflake_id`. - - Returns: - The per-millisecond sequence counter packed into ``snowflake_id``, in - the range ``[0, SEQUENCE_ID_MAX]``. - """ - # TODO: реализуйте функцию - return 0 + return sequence_id def generate_snowflake_id( From 2af0c8083b601df14b0e6db9e064baab9a93d7f9 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Mon, 21 Sep 2026 15:33:24 +0300 Subject: [PATCH 06/31] modificed 'generate_snowflake_id' --- src/part1/snowflake.py | 42 +++++++++++++++++------------------------- 1 file changed, 17 insertions(+), 25 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 4d6217af..2abce632 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -55,28 +55,20 @@ def generate_snowflake_id( node_id: int = NODE_ID_DEFAULT, epoch_ms: int = EPOCH_MS_DEFAULT, ) -> int | None: - """Build and return a Snowflake identifier for the current millisecond. - - The function is stateless: the caller passes the per-millisecond sequence - counter explicitly. It is the caller's responsibility to increment - ``sequence_id`` for identifiers minted within the same millisecond and to - reset it once the clock advances. - - Args: - sequence_id: The per-millisecond sequence counter, in the range - ``[0, SEQUENCE_ID_MAX]``. - node_id: The identifier of this node, in the range ``[0, NODE_ID_MAX]``. - Optional; defaults to ``NODE_ID_DEFAULT``. - epoch_ms: The start of the epoch as Unix milliseconds. Optional; - defaults to the original Twitter epoch (2010-11-04 01:42:54.657 - UTC). - - Returns: - The Snowflake identifier as a positive 63-bit integer, or ``None`` if - ``node_id`` is outside ``[0, NODE_ID_MAX]``, ``sequence_id`` is outside - ``[0, SEQUENCE_ID_MAX]``, or the elapsed time no longer fits in the - timestamp field (roughly 69 years after ``epoch_ms``). In each of those - cases an explanatory message is printed to stdout first. - """ - # TODO: реализуйте функцию - return 0 + + if (node_id < 0 or node_id > NODE_ID_MAX): + print('node_id must be in range[0; 1023]') + return None + + + elif (sequence_id < 0 or sequence_id > SEQUENCE_ID_MAX): + print('sequence_id must be in [0; 4095]') + return None + + + elif (decode_timestamp_ms(epoch_ms) > TIMESTAMP_MS_MAX): + print('overflows') + return None + + + return read_current_millis(epoch_ms) << 22 | node_id << 12 | sequence_id From ca03d8378031869a5d0bb99b9bec304251ed760f Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Mon, 21 Sep 2026 15:46:10 +0300 Subject: [PATCH 07/31] fixed shorcoming --- src/part1/constants.py | 28 +++------------------------- src/part1/snowflake.py | 39 ++++++++------------------------------- 2 files changed, 11 insertions(+), 56 deletions(-) diff --git a/src/part1/constants.py b/src/part1/constants.py index a01b7b98..afc19ecf 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -1,37 +1,15 @@ -"""Bit layout and default epoch for the Twitter Snowflake ID generator. - -A Snowflake identifier is a 63-bit positive integer packed as follows, from -the most significant bit downwards: - - 1 bit unused sign bit, always zero - 41 bits milliseconds elapsed since a custom epoch - 10 bits node identifier - 12 bits per-millisecond sequence counter - -The shift and mask constants should be derived from the bit widths so that -changing a width keeps everything else consistent. -""" - from typing import Final - - -# Twitter's original Snowflake epoch: 2010-11-04 01:42:54.657 UTC. EPOCH_MS_DEFAULT: Final[int] = 1288834974657 -# Node identifier used when the caller does not supply one. NODE_ID_DEFAULT: Final[int] = 1 -# Width of each field, in bits. TIMESTAMP_BITS: Final[int] = 41 NODE_ID_BITS: Final[int] = 10 SEQUENCE_ID_BITS: Final[int] = 12 -# Largest value each field can hold. -TIMESTAMP_MS_MAX: Final[int] = 2 ** TIMESTAMP_BITS - 1 -NODE_ID_MAX: Final[int] = 2 ** NODE_ID_BITS - 1 -SEQUENCE_ID_MAX: Final[int] = 2 ** SEQUENCE_ID_BITS - 1 -# Здесь можно добавить собственные вспомогательные константы -# (например, сдвиги полей при сборке идентификатора). +TIMESTAMP_MS_MAX: Final[int] = 2**TIMESTAMP_BITS - 1 +NODE_ID_MAX: Final[int] = 2**NODE_ID_BITS - 1 +SEQUENCE_ID_MAX: Final[int] = 2**SEQUENCE_ID_BITS - 1 diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 2abce632..7c441711 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -1,21 +1,6 @@ -"""Twitter Snowflake identifier generator. +import time -Snowflake produces roughly time-ordered 64-bit integer identifiers without -coordination between nodes. Each identifier packs the milliseconds elapsed -since a custom epoch, a node identifier and a per-millisecond sequence counter -into a single 63-bit positive integer (see ``constants`` for the layout). - -The public entry point is :func:`generate_snowflake_id`. It is stateless: the -caller passes the sequence counter on every call and is responsible for -advancing it within a millisecond and resetting it when the clock ticks over. - -Each packed field can be read back on its own with :func:`decode_timestamp_ms`, -:func:`decode_node_id` and :func:`decode_sequence_id`. -""" - -import time # noqa: F401 - -from .constants import ( # noqa: F401 +from .constants import ( EPOCH_MS_DEFAULT, NODE_ID_DEFAULT, NODE_ID_MAX, @@ -27,14 +12,12 @@ def read_current_millis(epoch_ms: int) -> int: current_time = int(time.time() * 1000) - return current_time - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: default_time = snowflake_id >> 22 - return default_time + epoch_ms @@ -55,20 +38,14 @@ def generate_snowflake_id( node_id: int = NODE_ID_DEFAULT, epoch_ms: int = EPOCH_MS_DEFAULT, ) -> int | None: - - if (node_id < 0 or node_id > NODE_ID_MAX): - print('node_id must be in range[0; 1023]') + if node_id < 0 or node_id > NODE_ID_MAX: + print("node_id must be in range[0; 1023]") return None - - - elif (sequence_id < 0 or sequence_id > SEQUENCE_ID_MAX): - print('sequence_id must be in [0; 4095]') + elif sequence_id < 0 or sequence_id > SEQUENCE_ID_MAX: + print("sequence_id must be in [0; 4095]") return None - - - elif (decode_timestamp_ms(epoch_ms) > TIMESTAMP_MS_MAX): - print('overflows') + elif decode_timestamp_ms(epoch_ms) > TIMESTAMP_MS_MAX: + print("overflows") return None - return read_current_millis(epoch_ms) << 22 | node_id << 12 | sequence_id From a1ea3f21e30e414ce0642e4a0f4cf7543de0d061 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 29 Sep 2026 21:08:49 +0300 Subject: [PATCH 08/31] Modificed storage.py --- src/part1/snowflake.py | 2 +- src/part2/storage.py | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 7c441711..8f332ff1 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -48,4 +48,4 @@ def generate_snowflake_id( print("overflows") return None - return read_current_millis(epoch_ms) << 22 | node_id << 12 | sequence_id + return read_current_millis(epoch_ms) << 22 | node_id << 12 | sequence_id \ No newline at end of file diff --git a/src/part2/storage.py b/src/part2/storage.py index b63d5fc7..35821c5f 100644 --- a/src/part2/storage.py +++ b/src/part2/storage.py @@ -26,9 +26,9 @@ # TODO: задайте позиции полей внутри кортежа Product PRODUCT_ID_INDEX: Final = 0 -NAME_INDEX: Final = 0 -PRICE_INDEX: Final = 0 -QUANTITY_INDEX: Final = 0 +NAME_INDEX: Final = 1 +PRICE_INDEX: Final = 2 +QUANTITY_INDEX: Final = 3 # TODO: задайте идентификатор первого товара в пустом хранилище -PRODUCT_ID_MIN: Final[int] = 0 +PRODUCT_ID_MIN: Final[int] = 1 From 79a15174617d03c4de9893bdd3f83f404d07b039 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 29 Sep 2026 21:23:52 +0300 Subject: [PATCH 09/31] Modificed utils.py --- src/part2/utils.py | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/src/part2/utils.py b/src/part2/utils.py index ec0348d3..7f6e5322 100644 --- a/src/part2/utils.py +++ b/src/part2/utils.py @@ -11,19 +11,11 @@ # TODO: задайте число знаков после запятой и шаг квантования -PRICE_PRECISION: Final[int] = 0 -PRICE_STEP: Final = Decimal(0) +PRICE_PRECISION: Final[int] = 2 +PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) def normalize_price(price: Decimal) -> Decimal: - """Round a price to the precision every stored record uses. + correct_price = price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) - Args: - price: The raw price amount. - - Returns: - ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, - with halves rounded up. - """ - # TODO: реализуйте функцию - return Decimal(0) + return correct_price From 512f4c329f302b85b6c235c7501d6f11e861b4a1 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 29 Sep 2026 21:58:58 +0300 Subject: [PATCH 10/31] modificed crud.py --- src/part2/crud.py | 106 +++++++++++++++------------------------------- 1 file changed, 34 insertions(+), 72 deletions(-) diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..5cafa888 100644 --- a/src/part2/crud.py +++ b/src/part2/crud.py @@ -24,97 +24,59 @@ def generate_product_id(storage: list[Product]) -> int: - """Choose the identifier for the next product added to ``storage``. + if len(storage) == 0: + return PRODUCT_ID_MIN + mx = max(product[PRODUCT_ID_INDEX] for product in storage) + 1 - Args: - storage: The product store to inspect. - - Returns: - One past the greatest identifier currently held in ``storage``, or - :data:`~src.part2.storage.PRODUCT_ID_MIN` when ``storage`` is - empty. - """ - # TODO: реализуйте функцию - return 0 + return mx def create_product( storage: list[Product], fields: tuple[str, Decimal, int] ) -> int | None: - """Append a new product to ``storage`` and return its new identifier. + for product in storage: + if product[NAME_INDEX] == fields[0]: + print(f"product name {product[NAME_INDEX]} is already taken.") + return None - Args: - storage: The product store to append to; modified in place on - success. - fields: A ``(name, price, quantity)`` tuple describing the product. - ``price`` is a :class:`~decimal.Decimal` amount and is rounded - to the stored money precision before it is saved. + product_id = generate_product_id(storage) + name, price, quantity = fields + new_product = (product_id, name, normalize_price(price), quantity) + + storage.append(new_product) - Returns: - The identifier generated for the new product, or ``None`` when a - product with the same name already exists. In the ``None`` case - ``storage`` is left unchanged and a message naming the clashing - name is printed. - """ - # TODO: реализуйте функцию - return 0 + return product_id def read_product(storage: list[Product], product_id: int) -> Product | None: - """Return the product stored under ``product_id``. - - Args: - storage: The product store to search. - product_id: The identifier to look up. - - Returns: - The matching ``(product_id, name, price, quantity)`` record, or - ``None`` when no product carries that identifier (a message is - printed in that case). - """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + return product + print(f"no product with id <{product_id}>") + return None def update_product( storage: list[Product], product_id: int, fields: tuple[str, Decimal, int], ) -> Product | None: - """Overwrite the fields of the product stored under ``product_id``. + for i in range(len(storage)): + if storage[i][PRODUCT_ID_INDEX] == product_id: + name, price, quality = fields + new_product = (product_id, name, normalize_price(price), quality) + storage[i] = new_product + return new_product - The identifier itself is preserved; only ``name``, ``price`` and - ``quantity`` are replaced. - - Args: - storage: The product store to modify; the matching record is - replaced in place on success. - product_id: The identifier of the product to change. - fields: A ``(name, price, quantity)`` tuple with the new values. - ``price`` is a :class:`~decimal.Decimal` amount and is rounded - to the stored money precision before it is saved. - - Returns: - The updated ``(product_id, name, price, quantity)`` record, or - ``None`` when no product carries that identifier (``storage`` is - left unchanged and a message is printed). - """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + print(f"no product with id <{product_id}>") + return None def delete_product(storage: list[Product], product_id: int) -> int | None: - """Remove the product stored under ``product_id`` from ``storage``. - - Args: - storage: The product store to remove from; modified in place on - success. - product_id: The identifier of the product to remove. - - Returns: - ``product_id`` when a product was removed, or ``None`` when no - product carried that identifier (``storage`` is left unchanged and - a message is printed). - """ - # TODO: реализуйте функцию - return 0 + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + storage.remove(product) + return product_id + + print(f"no product with id <{product_id}>") + return None From d8e8330da607ac7213ae0f10278f32f971c5e302 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 30 Sep 2026 16:11:24 +0300 Subject: [PATCH 11/31] modificed cart.py --- src/part2/cart.py | 104 +++++++++++++++++++++++++--------------------- 1 file changed, 57 insertions(+), 47 deletions(-) diff --git a/src/part2/cart.py b/src/part2/cart.py index 063f9aea..609890e8 100644 --- a/src/part2/cart.py +++ b/src/part2/cart.py @@ -16,6 +16,7 @@ NAME_INDEX, PRICE_INDEX, QUANTITY_INDEX, + PRODUCT_ID_INDEX, Product, ) @@ -24,7 +25,7 @@ # TODO: задайте позиции полей внутри кортежа CartLine LINE_PRODUCT_ID_INDEX: Final = 0 -LINE_QUANTITY_INDEX: Final = 0 +LINE_QUANTITY_INDEX: Final = 1 def add_to_cart( @@ -33,28 +34,33 @@ def add_to_cart( product_id: int, quantity: int, ) -> CartLine | None: - """Move ``quantity`` units of ``product_id`` from the store into ``cart``. - - The product is looked up in ``storage``. If it is missing, a message is - printed (by :func:`~src.part2.crud.read_product`) and nothing - changes. If the store holds fewer units than requested, an explanatory - message is printed and nothing changes. Otherwise the store record is - decremented by ``quantity`` and the cart line for ``product_id`` gains - ``quantity`` units -- a new line is created when the cart had none. - - Args: - storage: The product store to draw stock from; modified in place on - success. - cart: The cart to add the units to; modified in place on success. - product_id: The identifier of the product to add. - quantity: Number of units to move into the cart. - - Returns: - The cart line for ``product_id`` after the addition, or ``None`` - when the product is unknown or the store cannot cover the request. - """ - # TODO: реализуйте функцию - return (0, 0) + product = read_product(storage, product_id) + if product is None: + return None + + + for i in range(len(storage)): + product = storage[i] + if product_id == product[PRODUCT_ID_INDEX]: + quantity_storage = product[QUANTITY_INDEX] + if quantity > quantity_storage: + print(f"not enough stock for product <{product_id}>: {quantity_storage} available, {quantity} requested") + return None + + name, price = product[NAME_INDEX], product[PRICE_INDEX] + new_product = (product_id, name, price, quantity_storage - quantity) + storage[i] = new_product + + for j in range(len(cart)): + cur_cart = cart[j] + if cur_cart[LINE_PRODUCT_ID_INDEX] == product_id: + new_cart = (cur_cart[LINE_PRODUCT_ID_INDEX], cur_cart[LINE_QUANTITY_INDEX] + quantity) + cart[j] = new_cart + return new_cart + + new_cart = (product_id, quantity) + cart.append(new_cart) + return new_cart def remove_from_cart( @@ -63,27 +69,31 @@ def remove_from_cart( product_id: int, quantity: int, ) -> CartLine | None: - """Move ``quantity`` units of ``product_id`` from ``cart`` back to the store. - - The cart line for ``product_id`` is looked up. If there is none, a - message is printed and nothing changes. If the line holds fewer units - than requested, an explanatory message is printed and nothing changes. - Otherwise the cart line loses ``quantity`` units -- the line is dropped - when it reaches zero -- and the store record gains ``quantity`` units - back. - - Args: - storage: The product store to return stock to; modified in place on - success. - cart: The cart to take the units from; modified in place on - success. - product_id: The identifier of the product to remove. - quantity: Number of units to move back into the store. - - Returns: - The cart line for ``product_id`` after the removal (a quantity of - zero means the line was dropped), or ``None`` when the cart has no - line for the product or holds too few units. - """ - # TODO: реализуйте функцию - return (0, 0) + for i in range(len(cart)): + id, quantity_cart = cart[i] + if id == product_id: + if quantity > quantity_cart: + print(f'cart holds only {quantity_cart} unit(s) of product <{product_id}>, cannot remove {quantity}') + return None + + product = read_product(storage, product_id) + if product is None: + return None + + new_product = (product[NAME_INDEX], product[PRICE_INDEX], product[QUANTITY_INDEX] + quantity) + update_product(storage, product_id, new_product) + + if quantity == quantity_cart: + cart.pop(i) + return (product_id, 0) + + cart[i] = (product_id, quantity_cart - quantity) + + return cart[i] + + print(f'product <{product_id}> is not in the cart') + return None + + + + \ No newline at end of file From 7690602a4bfe4801fbe9bb4c9cf0b8f0b4c1b18f Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 30 Sep 2026 16:15:08 +0300 Subject: [PATCH 12/31] delete small mistakes --- src/part1/snowflake.py | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 8f332ff1..5e1d0ecc 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -6,6 +6,8 @@ NODE_ID_MAX, SEQUENCE_ID_MAX, TIMESTAMP_MS_MAX, + NODE_ID_BITS, + SEQUENCE_ID_BITS, ) @@ -16,19 +18,19 @@ def read_current_millis(epoch_ms: int) -> int: def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: - default_time = snowflake_id >> 22 + default_time = snowflake_id >> (NODE_ID_DEFAULT + SEQUENCE_ID_BITS) return default_time + epoch_ms def decode_node_id(snowflake_id: int) -> int: - node_id = (snowflake_id >> 12) & 0b1111111111 + node_id = (snowflake_id >> 12) & NODE_ID_BITS return node_id def decode_sequence_id(snowflake_id: int) -> int: - sequence_id = snowflake_id & 0b111111111111 + sequence_id = snowflake_id & SEQUENCE_ID_BITS return sequence_id @@ -48,4 +50,4 @@ def generate_snowflake_id( print("overflows") return None - return read_current_millis(epoch_ms) << 22 | node_id << 12 | sequence_id \ No newline at end of file + return read_current_millis(epoch_ms) << (NODE_ID_BITS + SEQUENCE_ID_BITS) | node_id << SEQUENCE_ID_BITS | sequence_id \ No newline at end of file From 34e14673de9669e3cb68a4e1c61070d3ef805020 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 30 Sep 2026 16:24:38 +0300 Subject: [PATCH 13/31] correct mistakes --- src/part1/snowflake.py | 10 +++++++--- src/part2/cart.py | 45 ++++++++++++++++++++---------------------- src/part2/crud.py | 21 ++++---------------- src/part2/utils.py | 11 +---------- 4 files changed, 33 insertions(+), 54 deletions(-) diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index 5e1d0ecc..13997f48 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -2,12 +2,12 @@ from .constants import ( EPOCH_MS_DEFAULT, + NODE_ID_BITS, NODE_ID_DEFAULT, NODE_ID_MAX, + SEQUENCE_ID_BITS, SEQUENCE_ID_MAX, TIMESTAMP_MS_MAX, - NODE_ID_BITS, - SEQUENCE_ID_BITS, ) @@ -50,4 +50,8 @@ def generate_snowflake_id( print("overflows") return None - return read_current_millis(epoch_ms) << (NODE_ID_BITS + SEQUENCE_ID_BITS) | node_id << SEQUENCE_ID_BITS | sequence_id \ No newline at end of file + return ( + read_current_millis(epoch_ms) << (NODE_ID_BITS + SEQUENCE_ID_BITS) + | node_id << SEQUENCE_ID_BITS + | sequence_id + ) diff --git a/src/part2/cart.py b/src/part2/cart.py index 609890e8..1671a72b 100644 --- a/src/part2/cart.py +++ b/src/part2/cart.py @@ -1,22 +1,11 @@ -"""Shopping-cart operations layered on top of the product store. - -The cart is a plain list of tuples, one :data:`CartLine` -- -``(product_id, quantity)`` -- per distinct product. Moving units between the -store and the cart keeps the two sides in balance: :func:`add_to_cart` takes -units out of stock, :func:`remove_from_cart` puts them back. - -Like the CRUD layer, the failure path never raises -- the operation prints -an explanatory message to stdout and returns ``None``. -""" - from typing import Final -from .crud import read_product, update_product # noqa: F401 -from .storage import ( # noqa: F401 +from .crud import read_product, update_product +from .storage import ( NAME_INDEX, PRICE_INDEX, - QUANTITY_INDEX, PRODUCT_ID_INDEX, + QUANTITY_INDEX, Product, ) @@ -38,13 +27,14 @@ def add_to_cart( if product is None: return None - for i in range(len(storage)): product = storage[i] if product_id == product[PRODUCT_ID_INDEX]: quantity_storage = product[QUANTITY_INDEX] if quantity > quantity_storage: - print(f"not enough stock for product <{product_id}>: {quantity_storage} available, {quantity} requested") + print( + f"not enough stock for product <{product_id}>: {quantity_storage} available, {quantity} requested" + ) return None name, price = product[NAME_INDEX], product[PRICE_INDEX] @@ -54,7 +44,10 @@ def add_to_cart( for j in range(len(cart)): cur_cart = cart[j] if cur_cart[LINE_PRODUCT_ID_INDEX] == product_id: - new_cart = (cur_cart[LINE_PRODUCT_ID_INDEX], cur_cart[LINE_QUANTITY_INDEX] + quantity) + new_cart = ( + cur_cart[LINE_PRODUCT_ID_INDEX], + cur_cart[LINE_QUANTITY_INDEX] + quantity, + ) cart[j] = new_cart return new_cart @@ -62,6 +55,8 @@ def add_to_cart( cart.append(new_cart) return new_cart + return None + def remove_from_cart( storage: list[Product], @@ -73,14 +68,20 @@ def remove_from_cart( id, quantity_cart = cart[i] if id == product_id: if quantity > quantity_cart: - print(f'cart holds only {quantity_cart} unit(s) of product <{product_id}>, cannot remove {quantity}') + print( + f"cart holds only {quantity_cart} unit(s) of product <{product_id}>, cannot remove {quantity}" + ) return None product = read_product(storage, product_id) if product is None: return None - new_product = (product[NAME_INDEX], product[PRICE_INDEX], product[QUANTITY_INDEX] + quantity) + new_product = ( + product[NAME_INDEX], + product[PRICE_INDEX], + product[QUANTITY_INDEX] + quantity, + ) update_product(storage, product_id, new_product) if quantity == quantity_cart: @@ -91,9 +92,5 @@ def remove_from_cart( return cart[i] - print(f'product <{product_id}> is not in the cart') + print(f"product <{product_id}> is not in the cart") return None - - - - \ No newline at end of file diff --git a/src/part2/crud.py b/src/part2/crud.py index 5cafa888..3fc9ab49 100644 --- a/src/part2/crud.py +++ b/src/part2/crud.py @@ -1,26 +1,12 @@ -"""Create/read/update/delete operations over the in-memory product store. - -Every operation takes the store -- a list of -:data:`~src.part2.storage.Product` tuples -- as its first argument and -works on it in place. The failure path never raises: the operation prints -an explanatory message to stdout and returns ``None``. - -The identifier of a new product is derived from the store itself -(:func:`generate_product_id`): one past the greatest identifier in use, or -:data:`~src.part2.storage.PRODUCT_ID_MIN` when the store is empty. -Product names are kept unique -- :func:`create_product` refuses a name that -is already taken. -""" - from decimal import Decimal -from .storage import ( # noqa: F401 +from .storage import ( NAME_INDEX, PRODUCT_ID_INDEX, PRODUCT_ID_MIN, Product, ) -from .utils import normalize_price # noqa: F401 +from .utils import normalize_price def generate_product_id(storage: list[Product]) -> int: @@ -42,7 +28,7 @@ def create_product( product_id = generate_product_id(storage) name, price, quantity = fields new_product = (product_id, name, normalize_price(price), quantity) - + storage.append(new_product) return product_id @@ -56,6 +42,7 @@ def read_product(storage: list[Product], product_id: int) -> Product | None: print(f"no product with id <{product_id}>") return None + def update_product( storage: list[Product], product_id: int, diff --git a/src/part2/utils.py b/src/part2/utils.py index 7f6e5322..659d1d07 100644 --- a/src/part2/utils.py +++ b/src/part2/utils.py @@ -1,16 +1,7 @@ -"""Standalone helpers shared by the hw4 storage and CRUD modules. - -For now this is limited to money handling: :func:`normalize_price` rounds a -raw :class:`~decimal.Decimal` amount to the fixed number of fractional -digits (:data:`PRICE_PRECISION`) that every stored price uses, keeping -currency values free of binary floating-point error. -""" - -from decimal import ROUND_HALF_UP, Decimal # noqa: F401 +from decimal import ROUND_HALF_UP, Decimal from typing import Final -# TODO: задайте число знаков после запятой и шаг квантования PRICE_PRECISION: Final[int] = 2 PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) From bcea0d50751814376ca9685085c5e3b83cced8fd Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 30 Sep 2026 16:41:22 +0300 Subject: [PATCH 14/31] add new function 'find_cart_line' --- src/part2/cart.py | 18 +++++++++++++++++- src/part2/storage.py | 24 ++---------------------- 2 files changed, 19 insertions(+), 23 deletions(-) diff --git a/src/part2/cart.py b/src/part2/cart.py index 1671a72b..a53f3570 100644 --- a/src/part2/cart.py +++ b/src/part2/cart.py @@ -58,12 +58,29 @@ def add_to_cart( return None +def find_cart_line( + cart: list[CartLine], + product_id: int, +) -> CartLine | None: + for product in cart: + if product_id == product[LINE_PRODUCT_ID_INDEX]: + return product + + return None + + def remove_from_cart( storage: list[Product], cart: list[CartLine], product_id: int, quantity: int, ) -> CartLine | None: + cart_line = find_cart_line(cart, product_id) + + if cart_line is None: + print(f"product <{product_id}> is not in the cart") + return None + for i in range(len(cart)): id, quantity_cart = cart[i] if id == product_id: @@ -92,5 +109,4 @@ def remove_from_cart( return cart[i] - print(f"product <{product_id}> is not in the cart") return None diff --git a/src/part2/storage.py b/src/part2/storage.py index 35821c5f..03128124 100644 --- a/src/part2/storage.py +++ b/src/part2/storage.py @@ -1,34 +1,14 @@ -"""In-memory product store for the shop CRUD exercise. - -The store is deliberately primitive: a plain list of tuples, with no -persistence, no indexing and no schema enforcement. Each element is a -:data:`Product` record -- a ``(product_id, name, price, quantity)`` tuple -where: - -* ``product_id`` -- unique positive integer key, assigned by the create - operation in :mod:`src.part2.crud`; -* ``name`` -- human-readable product name, unique across the store; -* ``price`` -- price of a single unit, held as a :class:`~decimal.Decimal` - amount rounded to a fixed number of decimal places (see - :func:`src.part2.utils.normalize_price`) so that money is never - subject to binary floating-point error; -* ``quantity`` -- number of units currently in stock. - -Field positions are exposed as ``*_INDEX`` constants so callers never -hard-code tuple offsets. -""" - from decimal import Decimal from typing import Final type Product = tuple[int, str, Decimal, int] -# TODO: задайте позиции полей внутри кортежа Product + PRODUCT_ID_INDEX: Final = 0 NAME_INDEX: Final = 1 PRICE_INDEX: Final = 2 QUANTITY_INDEX: Final = 3 -# TODO: задайте идентификатор первого товара в пустом хранилище + PRODUCT_ID_MIN: Final[int] = 1 From 68d09612349fd89ec976882ea0a5e5fd8715f417 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 7 Oct 2026 05:07:18 +0300 Subject: [PATCH 15/31] modificed storage.py --- src/part3/storage.py | 33 ++++++--------------------------- 1 file changed, 6 insertions(+), 27 deletions(-) diff --git a/src/part3/storage.py b/src/part3/storage.py index c5e34be5..7d81ce1f 100644 --- a/src/part3/storage.py +++ b/src/part3/storage.py @@ -1,35 +1,14 @@ -"""In-memory product store for the shop CRUD exercise. - -The store is deliberately primitive: a plain list of tuples, with no -persistence, no indexing and no schema enforcement. Each element is a -:data:`Product` record -- a ``(product_id, name, price, quantity)`` tuple -where: - -* ``product_id`` -- unique positive integer key, assigned by the create - operation in :mod:`src.part3.crud`; -* ``name`` -- human-readable product name, unique across the store; -* ``price`` -- price of a single unit, held as a :class:`~decimal.Decimal` - amount rounded to a fixed number of decimal places (see - :func:`src.part3.utils.normalize_price`) so that money is never - subject to binary floating-point error; -* ``quantity`` -- number of units currently in stock. - -Field positions are exposed as ``*_INDEX`` constants so callers never -hard-code tuple offsets. -""" - from decimal import Decimal from typing import Final type Product = tuple[int, str, Decimal, int] -# TODO: задайте позиции полей внутри кортежа Product (используйте своё решение -# части 2) + PRODUCT_ID_INDEX: Final = 0 -NAME_INDEX: Final = 0 -PRICE_INDEX: Final = 0 -QUANTITY_INDEX: Final = 0 +NAME_INDEX: Final = 1 +PRICE_INDEX: Final = 2 +QUANTITY_INDEX: Final = 3 + -# TODO: задайте идентификатор первого товара в пустом хранилище -PRODUCT_ID_MIN: Final[int] = 0 +PRODUCT_ID_MIN: Final[int] = 1 \ No newline at end of file From 1e534bc319478066481c43732017f926e0c2722b Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 7 Oct 2026 06:13:42 +0300 Subject: [PATCH 16/31] modificed utils.py --- src/part3/crud.py | 50 +++++++---------------- src/part3/utils.py | 98 ++++++++++++++++++++++++---------------------- 2 files changed, 67 insertions(+), 81 deletions(-) diff --git a/src/part3/crud.py b/src/part3/crud.py index 68811d7e..9f837530 100644 --- a/src/part3/crud.py +++ b/src/part3/crud.py @@ -30,18 +30,11 @@ def generate_product_id(storage: list[Product]) -> int: - """Choose the identifier for the next product added to ``storage``. + if len(storage) == 0: + return PRODUCT_ID_MIN + mx = max(product[PRODUCT_ID_INDEX] for product in storage) + 1 - Args: - storage: The product store to inspect. - - Returns: - One past the greatest identifier currently held in ``storage``, or - :data:`~src.part3.storage.PRODUCT_ID_MIN` when ``storage`` is - empty. - """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return 0 + return mx def create_product( @@ -69,19 +62,12 @@ def create_product( def read_product(storage: list[Product], product_id: int) -> Product | None: - """Return the product stored under ``product_id``. + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + return product - Args: - storage: The product store to search. - product_id: The identifier to look up. - - Returns: - The matching ``(product_id, name, price, quantity)`` record, or - ``None`` when no product carries that identifier (a message is - printed in that case). - """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return (0, "", Decimal(0), 0) + print(f"no product with id <{product_id}>") + return None def update_product( @@ -115,17 +101,11 @@ def update_product( def delete_product(storage: list[Product], product_id: int) -> int | None: - """Remove the product stored under ``product_id`` from ``storage``. + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + storage.remove(product) + return product_id - Args: - storage: The product store to remove from; modified in place on - success. - product_id: The identifier of the product to remove. + print(f"no product with id <{product_id}>") + return None - Returns: - ``product_id`` when a product was removed, or ``None`` when no - product carried that identifier (``storage`` is left unchanged and - a message is printed). - """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return 0 diff --git a/src/part3/utils.py b/src/part3/utils.py index 318ded0b..ef84f3e1 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -22,74 +22,80 @@ from typing import Final from .storage import Product +from .storage import ( + PRODUCT_ID_INDEX, + NAME_INDEX, + PRICE_INDEX, + QUANTITY_INDEX, +) # Number of fractional digits every stored price is rounded to. # Quantisation step derived from PRICE_PRECISION, e.g. Decimal("0.01"). # TODO: задайте число знаков после запятой и шаг квантования (используйте своё # решение части 2) -PRICE_PRECISION: Final[int] = 0 -PRICE_STEP: Final = Decimal(0) +PRICE_PRECISION: Final[int] = 2 +PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) # Column headers of the table produced by get_storage_str_representation, # left to right. The width of each column is not fixed here -- it is # measured per call from the data (see the function). # TODO: задайте заголовки столбцов таблицы -TABLE_HEADERS: Final[tuple[str, ...]] = () +TABLE_HEADERS: Final[tuple[str, ...]] = ("ID", "name", "price", "quantity") def normalize_price(price: Decimal) -> Decimal: - """Round a price to the precision every stored record uses. + correct_price = price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) - Args: - price: The raw price amount. - - Returns: - ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, - with halves rounded up. - """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return Decimal(0) + return correct_price def normalize_product_name(name: str) -> str: - """Reduce a product name to the canonical form the store keeps. - - Args: - name: The raw product name. + correct_name = [word.lower() for word in name.split()] - Returns: - ``name`` with every leading and trailing whitespace character - removed, every internal run of whitespace (spaces, tabs and the - like) collapsed to a single space, and the rest lower-cased. For - example ``"abc def\tghi\tjkl"`` becomes ``"abc def ghi jkl"``. - The result is an empty string when ``name`` holds nothing but - whitespace. - """ - # TODO: реализуйте функцию - return "" + return " ".join(correct_name) + # TODO: при необходимости добавьте свои вспомогательные функции def get_storage_str_representation(storage: list[Product]) -> str: - """Render the product store as a text table with data-sized columns. - - The table has the columns named by :data:`TABLE_HEADERS` -- id, name, - price and quantity. Each column is made exactly as wide as the longest - value it carries in this call (its header counted), so the columns - line up when the string is printed to a terminal and no value is ever - truncated. - - Args: - storage: The product store to render. - - Returns: - A multi-line string: a header row, a dashed separator row, then - one row per product in ``storage`` in list order. When ``storage`` - is empty only the header and separator rows are returned, sized to - the header labels. - """ - # TODO: реализуйте функцию - return "" + len_headers = [ + len(TABLE_HEADERS[0]), + len(TABLE_HEADERS[1]), + len(TABLE_HEADERS[2]), + len(TABLE_HEADERS[3]), + ] + + for product in storage: + len_id = len(str(product[PRODUCT_ID_INDEX])) + len_name = len(str(product[NAME_INDEX])) + len_price = len(str(product[PRICE_INDEX])) + len_quantity = len(str(product[QUANTITY_INDEX])) + + len_headers = [ + max(len_headers[0], len_id), + max(len_headers[1], len_name), + max(len_headers[2], len_price), + max(len_headers[3], len_quantity), + ] + + s = (f"| ID {' ' * (len_headers[0] - 2)}| name {' ' * (len_headers[1] - 4)}| price {' ' * (len_headers[2] - 5)}| quantity {' ' * (len_headers[3] - 8)}|\n" + f"|{'-' * (len_headers[0] + 2)}|{'-' * (len_headers[1] + 2)}|{'-' * (len_headers[2] + 2)}|{'-' * (len_headers[3] + 2)}|") + + for product in storage: + s += '\n' + + len_id = len(str(product[PRODUCT_ID_INDEX])) + len_name = len(str(product[NAME_INDEX])) + len_price = len(str(product[PRICE_INDEX])) + len_quantity = len(str(product[QUANTITY_INDEX])) + + s += f"| {product[PRODUCT_ID_INDEX]} {' ' * (len_headers[0] - len_id)}| {product[NAME_INDEX]} {' ' * (len_headers[1] - len_name)}| {product[PRICE_INDEX]} {' ' * (len_headers[2] - len_price)}| {product[QUANTITY_INDEX]} {' ' * (len_headers[3] - len_quantity)}|" + + + + + + return s From d299d64374486585f100016e73a9ee7c115c0f03 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Wed, 7 Oct 2026 07:16:27 +0300 Subject: [PATCH 17/31] modificed crud.py --- src/part3/crud.py | 86 ++++++++++++++++++++++++----------------------- 1 file changed, 44 insertions(+), 42 deletions(-) diff --git a/src/part3/crud.py b/src/part3/crud.py index 9f837530..551447a6 100644 --- a/src/part3/crud.py +++ b/src/part3/crud.py @@ -40,25 +40,25 @@ def generate_product_id(storage: list[Product]) -> int: def create_product( storage: list[Product], fields: tuple[str, Decimal, int] ) -> int | None: - """Append a new product to ``storage`` and return its new identifier. - - Args: - storage: The product store to append to; modified in place on - success. - fields: A ``(name, price, quantity)`` tuple describing the product. - ``name`` is normalised (surrounding whitespace stripped, - lower-cased) before it is stored or compared. ``price`` is a - :class:`~decimal.Decimal` amount and is rounded to the stored - money precision before it is saved. - - Returns: - The identifier generated for the new product, or ``None`` when - ``name`` is blank once normalised or a product with the same - normalised name already exists. In the ``None`` case ``storage`` - is left unchanged and an explanatory message is printed. - """ - # TODO: реализуйте функцию - return 0 + correct_name = normalize_product_name(fields[0]) + + if correct_name == '': + print("product name must not be blank") + return None + + for product in storage: + if product[NAME_INDEX] == correct_name: + print(f"product name '{correct_name}' is already taken") + return None + + product_id = generate_product_id(storage) + name, price, quantity = fields + new_product = (product_id, correct_name, normalize_price(price), quantity) + + storage.append(new_product) + + return product_id + def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -75,29 +75,31 @@ def update_product( product_id: int, fields: tuple[str, Decimal, int], ) -> Product | None: - """Overwrite the fields of the product stored under ``product_id``. - - The identifier itself is preserved; only ``name``, ``price`` and - ``quantity`` are replaced. - - Args: - storage: The product store to modify; the matching record is - replaced in place on success. - product_id: The identifier of the product to change. - fields: A ``(name, price, quantity)`` tuple with the new values. - ``price`` is a :class:`~decimal.Decimal` amount and is rounded - to the stored money precision before it is saved. - - Returns: - The updated ``(product_id, name, price, quantity)`` record, or - ``None`` when ``name`` is blank once normalised, no product - carries that identifier, or the normalised name is already taken - by another product. In every ``None`` case ``storage`` is left - unchanged and an explanatory message is printed. Renaming a - product to its own current name is allowed. - """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + correct_name = normalize_product_name(fields[0]) + + if correct_name == '': + print("product name must not be blank") + return None + + + for product in storage: + if product[NAME_INDEX] == correct_name and product_id != product[PRODUCT_ID_INDEX]: + print(f"product name '{correct_name}' is already taken") + return None + + for i in range(len(storage)): + product = storage[i] + if product_id == product[PRODUCT_ID_INDEX]: + new_product = (product_id, correct_name, normalize_price(fields[1]), fields[2]) + storage[i] = new_product + + return new_product + + print(f"no product with id <{product_id}>") + return None + + + def delete_product(storage: list[Product], product_id: int) -> int | None: From ee47f7af90455de4a23f888ff6e5eabd2f2db297 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Thu, 8 Oct 2026 11:12:55 +0300 Subject: [PATCH 18/31] update 'run_admin.py' --- src/part3/run_admin.py | 105 ++++++++++++++++++++++++++--------------- src/part3/utils.py | 4 -- 2 files changed, 67 insertions(+), 42 deletions(-) diff --git a/src/part3/run_admin.py b/src/part3/run_admin.py index c5feeb0b..db2d2fc9 100644 --- a/src/part3/run_admin.py +++ b/src/part3/run_admin.py @@ -39,57 +39,86 @@ update_product, ) from .storage import Product -from .utils import get_storage_str_representation # noqa: F401 +from .utils import get_storage_str_representation, normalize_price, normalize_product_name # noqa: F401 # TODO: задайте приглашение и текст справки -PROMPT: Final[str] = "" -HELP_TEXT: Final[str] = "" +PROMPT: Final[str] = "admin> " +HELP_TEXT: Final[str] = """Available commands: + help show this message + exit leave the console + show print the whole store as a table + create add a product, print its new id + read print the product with that id + update overwrite that product's fields + delete remove the product with that id + +For create and update the price and quantity are the last two words of the +line; everything before them is the product name, so it may contain spaces +(for example "Gibson SG Junior") and needs no quoting.""" def show_help() -> None: - """Print the command reference to stdout. + print(HELP_TEXT) - The text is the module-level :data:`HELP_TEXT` constant, printed as - is: a heading, one line per command with a short description, and a - note on how multi-word names are parsed. - """ - # TODO: реализуйте функцию + return None def print_result(result: object) -> None: - """Print a CRUD result to stdout unless it is ``None``. - - Args: - result: The value returned by a CRUD operation. ``None`` means the - operation already reported its own failure, so nothing is - printed in that case. - """ - # TODO: реализуйте функцию + if result is not None: + print(result) + def run_command(storage: list[Product], line: str) -> bool: - """Parse one console line and carry out the command it names. - - Args: - storage: The product store shared across the session; mutated in - place by the ``create``, ``update`` and ``delete`` commands. - line: One line of console input, already stripped of surrounding - whitespace. - - Returns: - ``True`` to keep the read-eval-print loop running, or ``False`` - once the ``exit`` command has been seen. A line that is not a - known command prints a notice and still returns ``True``. - - Raises: - ValueError: If an id or quantity argument of a CRUD command does - not parse as a base-10 integer. - decimal.InvalidOperation: If the price argument of ``create`` or - ``update`` does not parse as a decimal number. - """ - # TODO: реализуйте функцию - return False + match line.split(): + case ["help"]: + show_help() + return True + case ["exit"]: + return False + case ["show"]: + print(get_storage_str_representation(storage)) + return True + case ["create", *command]: + if len(command) < 3: + print(f"'{line}' is not a command") + return True + quantity = int(command[-1]) + price = normalize_price(Decimal(command[-2])) + name = normalize_product_name(" ".join(command[:-2])) + fields = (name, price, quantity) + answer = create_product(storage, fields) + print_result(answer) + return True + case ["read", id]: + id = int(id) + answer = read_product(storage, id) + print_result(answer) + return True + case ["update", id, *command]: + if len(command) < 3: + print(f"'{line}' is not a command") + return True + id = int(id) + quantity = int(command[-1]) + price = normalize_price(Decimal(command[-2])) + name = normalize_product_name(" ".join(command[:-2])) + fields = (name, price, quantity) + answer = update_product(storage, id, fields) + print_result(answer) + return True + case ["delete", id]: + id = int(id) + answer = delete_product(storage, id) + print_result(answer) + return True + case _: + print(f"'{line}' is not a command") + return True + + + def main() -> None: diff --git a/src/part3/utils.py b/src/part3/utils.py index ef84f3e1..63e6694a 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -94,8 +94,4 @@ def get_storage_str_representation(storage: list[Product]) -> str: s += f"| {product[PRODUCT_ID_INDEX]} {' ' * (len_headers[0] - len_id)}| {product[NAME_INDEX]} {' ' * (len_headers[1] - len_name)}| {product[PRICE_INDEX]} {' ' * (len_headers[2] - len_price)}| {product[QUANTITY_INDEX]} {' ' * (len_headers[3] - len_quantity)}|" - - - - return s From 9ee5a0a5064ddeb62c0792c3d074ead5935ae5c7 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Thu, 8 Oct 2026 11:31:03 +0300 Subject: [PATCH 19/31] fixed mistakes --- src/part2/utils.py | 1 - src/part3/crud.py | 60 ++++++++++++++++++++++-------------------- src/part3/run_admin.py | 33 ++++++++++------------- src/part3/storage.py | 2 +- src/part3/utils.py | 17 ++++++------ 5 files changed, 55 insertions(+), 58 deletions(-) diff --git a/src/part2/utils.py b/src/part2/utils.py index 53d25b6e..659d1d07 100644 --- a/src/part2/utils.py +++ b/src/part2/utils.py @@ -1,4 +1,3 @@ - from decimal import ROUND_HALF_UP, Decimal from typing import Final diff --git a/src/part3/crud.py b/src/part3/crud.py index 551447a6..2d519122 100644 --- a/src/part3/crud.py +++ b/src/part3/crud.py @@ -20,13 +20,13 @@ from decimal import Decimal -from .storage import ( # noqa: F401 +from .storage import ( NAME_INDEX, PRODUCT_ID_INDEX, PRODUCT_ID_MIN, Product, ) -from .utils import normalize_price, normalize_product_name # noqa: F401 +from .utils import normalize_price, normalize_product_name def generate_product_id(storage: list[Product]) -> int: @@ -42,7 +42,7 @@ def create_product( ) -> int | None: correct_name = normalize_product_name(fields[0]) - if correct_name == '': + if correct_name == "": print("product name must not be blank") return None @@ -50,15 +50,14 @@ def create_product( if product[NAME_INDEX] == correct_name: print(f"product name '{correct_name}' is already taken") return None - + product_id = generate_product_id(storage) - name, price, quantity = fields + _, price, quantity = fields new_product = (product_id, correct_name, normalize_price(price), quantity) - + storage.append(new_product) - + return product_id - def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -75,31 +74,35 @@ def update_product( product_id: int, fields: tuple[str, Decimal, int], ) -> Product | None: - correct_name = normalize_product_name(fields[0]) - - if correct_name == '': - print("product name must not be blank") - return None - + correct_name = normalize_product_name(fields[0]) - for product in storage: - if product[NAME_INDEX] == correct_name and product_id != product[PRODUCT_ID_INDEX]: - print(f"product name '{correct_name}' is already taken") - return None + if correct_name == "": + print("product name must not be blank") + return None - for i in range(len(storage)): - product = storage[i] - if product_id == product[PRODUCT_ID_INDEX]: - new_product = (product_id, correct_name, normalize_price(fields[1]), fields[2]) - storage[i] = new_product + for product in storage: + if ( + product[NAME_INDEX] == correct_name + and product_id != product[PRODUCT_ID_INDEX] + ): + print(f"product name '{correct_name}' is already taken") + return None - return new_product + for i in range(len(storage)): + product = storage[i] + if product_id == product[PRODUCT_ID_INDEX]: + new_product = ( + product_id, + correct_name, + normalize_price(fields[1]), + fields[2], + ) + storage[i] = new_product - print(f"no product with id <{product_id}>") - return None - - + return new_product + print(f"no product with id <{product_id}>") + return None def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -110,4 +113,3 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: print(f"no product with id <{product_id}>") return None - diff --git a/src/part3/run_admin.py b/src/part3/run_admin.py index db2d2fc9..3365362e 100644 --- a/src/part3/run_admin.py +++ b/src/part3/run_admin.py @@ -29,17 +29,21 @@ it. """ -from decimal import Decimal, InvalidOperation # noqa: F401 +from decimal import Decimal, InvalidOperation from typing import Final -from .crud import ( # noqa: F401 +from .crud import ( create_product, delete_product, read_product, update_product, ) from .storage import Product -from .utils import get_storage_str_representation, normalize_price, normalize_product_name # noqa: F401 +from .utils import ( + get_storage_str_representation, + normalize_price, + normalize_product_name, +) # TODO: задайте приглашение и текст справки @@ -61,13 +65,10 @@ def show_help() -> None: print(HELP_TEXT) - return None - def print_result(result: object) -> None: if result is not None: print(result) - def run_command(storage: list[Product], line: str) -> bool: @@ -88,38 +89,32 @@ def run_command(storage: list[Product], line: str) -> bool: price = normalize_price(Decimal(command[-2])) name = normalize_product_name(" ".join(command[:-2])) fields = (name, price, quantity) - answer = create_product(storage, fields) - print_result(answer) + print_result(create_product(storage, fields)) return True case ["read", id]: - id = int(id) - answer = read_product(storage, id) - print_result(answer) + find_id = int(id) + print_result(read_product(storage, find_id)) return True case ["update", id, *command]: if len(command) < 3: print(f"'{line}' is not a command") return True - id = int(id) + find_id = int(id) quantity = int(command[-1]) price = normalize_price(Decimal(command[-2])) name = normalize_product_name(" ".join(command[:-2])) fields = (name, price, quantity) - answer = update_product(storage, id, fields) - print_result(answer) + print_result(update_product(storage, find_id, fields)) return True case ["delete", id]: - id = int(id) - answer = delete_product(storage, id) + find_id = int(id) + answer = delete_product(storage, find_id) print_result(answer) return True case _: print(f"'{line}' is not a command") return True - - - def main() -> None: """Run the admin console until the ``exit`` command is entered. diff --git a/src/part3/storage.py b/src/part3/storage.py index 7d81ce1f..03128124 100644 --- a/src/part3/storage.py +++ b/src/part3/storage.py @@ -11,4 +11,4 @@ QUANTITY_INDEX: Final = 3 -PRODUCT_ID_MIN: Final[int] = 1 \ No newline at end of file +PRODUCT_ID_MIN: Final[int] = 1 diff --git a/src/part3/utils.py b/src/part3/utils.py index 63e6694a..c31baff6 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -18,15 +18,15 @@ the longest value it holds in that particular call. """ -from decimal import ROUND_HALF_UP, Decimal # noqa: F401 +from decimal import ROUND_HALF_UP, Decimal from typing import Final -from .storage import Product from .storage import ( - PRODUCT_ID_INDEX, NAME_INDEX, PRICE_INDEX, + PRODUCT_ID_INDEX, QUANTITY_INDEX, + Product, ) @@ -54,7 +54,6 @@ def normalize_product_name(name: str) -> str: correct_name = [word.lower() for word in name.split()] return " ".join(correct_name) - # TODO: при необходимости добавьте свои вспомогательные функции @@ -81,11 +80,13 @@ def get_storage_str_representation(storage: list[Product]) -> str: max(len_headers[3], len_quantity), ] - s = (f"| ID {' ' * (len_headers[0] - 2)}| name {' ' * (len_headers[1] - 4)}| price {' ' * (len_headers[2] - 5)}| quantity {' ' * (len_headers[3] - 8)}|\n" - f"|{'-' * (len_headers[0] + 2)}|{'-' * (len_headers[1] + 2)}|{'-' * (len_headers[2] + 2)}|{'-' * (len_headers[3] + 2)}|") + s = ( + f"| ID {' ' * (len_headers[0] - 2)}| name {' ' * (len_headers[1] - 4)}| price {' ' * (len_headers[2] - 5)}| quantity {' ' * (len_headers[3] - 8)}|\n" + f"|{'-' * (len_headers[0] + 2)}|{'-' * (len_headers[1] + 2)}|{'-' * (len_headers[2] + 2)}|{'-' * (len_headers[3] + 2)}|" + ) for product in storage: - s += '\n' + s += "\n" len_id = len(str(product[PRODUCT_ID_INDEX])) len_name = len(str(product[NAME_INDEX])) @@ -93,5 +94,5 @@ def get_storage_str_representation(storage: list[Product]) -> str: len_quantity = len(str(product[QUANTITY_INDEX])) s += f"| {product[PRODUCT_ID_INDEX]} {' ' * (len_headers[0] - len_id)}| {product[NAME_INDEX]} {' ' * (len_headers[1] - len_name)}| {product[PRICE_INDEX]} {' ' * (len_headers[2] - len_price)}| {product[QUANTITY_INDEX]} {' ' * (len_headers[3] - len_quantity)}|" - + return s From 1b41966d4315f9f7991ed1e7d8e7847c0183d83e Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Thu, 8 Oct 2026 23:35:01 +0300 Subject: [PATCH 20/31] correct update --- src/part3/crud.py | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/part3/crud.py b/src/part3/crud.py index 2d519122..bdf8bb5e 100644 --- a/src/part3/crud.py +++ b/src/part3/crud.py @@ -75,11 +75,20 @@ def update_product( fields: tuple[str, Decimal, int], ) -> Product | None: correct_name = normalize_product_name(fields[0]) - + flag = False if correct_name == "": print("product name must not be blank") return None + for i in range(len(storage)): + product = storage[i] + if product_id == product[PRODUCT_ID_INDEX]: + flag = True + + if not flag: + print(f"no product with id <{product_id}>") + return None + for product in storage: if ( product[NAME_INDEX] == correct_name From 5edaf6e4fbdc6bcd61262db19e92039b046b26aa Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 27 Oct 2026 12:38:58 +0300 Subject: [PATCH 21/31] storage.py was made --- src/part4/storage.py | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/part4/storage.py b/src/part4/storage.py index 9acedf07..a25f6253 100644 --- a/src/part4/storage.py +++ b/src/part4/storage.py @@ -40,6 +40,6 @@ # Name of each field inside a Product record. # TODO: задайте имена полей записи -NAME_KEY: Final = "" -PRICE_KEY: Final = "" -QUANTITY_KEY: Final = "" +NAME_KEY: Final = "name" +PRICE_KEY: Final = "price" +QUANTITY_KEY: Final = "quantity" From 89b82bc14ffe29f6d6bd4a53ce8f8e4395bdb233 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 27 Oct 2026 13:11:31 +0300 Subject: [PATCH 22/31] utils.py was made --- src/part4/utils.py | 97 ++++++++++++++++++++++------------------------ 1 file changed, 47 insertions(+), 50 deletions(-) diff --git a/src/part4/utils.py b/src/part4/utils.py index d2a940ea..9c2f5cae 100644 --- a/src/part4/utils.py +++ b/src/part4/utils.py @@ -18,10 +18,10 @@ the longest value it holds in that particular call. """ -from decimal import ROUND_HALF_UP, Decimal # noqa: F401 +from decimal import ROUND_HALF_UP, Decimal from typing import Final -from .storage import ( # noqa: F401 +from .storage import ( NAME_KEY, PRICE_KEY, QUANTITY_KEY, @@ -32,69 +32,66 @@ # Number of fractional digits every stored price is rounded to. # Quantisation step derived from PRICE_PRECISION, e.g. Decimal("0.01"). # TODO: задайте число знаков после запятой и шаг квантования (используйте своё -# решение части 3) -PRICE_PRECISION: Final[int] = 0 -PRICE_STEP: Final = Decimal(0) +# решение части 2) +PRICE_PRECISION: Final[int] = 2 +PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) # Column headers of the table produced by get_storage_str_representation, # left to right. The width of each column is not fixed here -- it is # measured per call from the data (see the function). -# TODO: задайте заголовки столбцов таблицы (используйте своё решение части 3) -TABLE_HEADERS: Final[tuple[str, ...]] = () +# TODO: задайте заголовки столбцов таблицы +TABLE_HEADERS: Final[tuple[str, ...]] = ("ID", "name", "price", "quantity") def normalize_price(price: Decimal) -> Decimal: - """Round a price to the precision every stored record uses. + correct_price = price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) - Args: - price: The raw price amount. - - Returns: - ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, - with halves rounded up. - """ - # TODO: реализуйте функцию (используйте своё решение части 3) - return Decimal(0) + return correct_price def normalize_product_name(name: str) -> str: - """Reduce a product name to the canonical form the store keeps. - - Args: - name: The raw product name. + correct_name = [word.lower() for word in name.split()] - Returns: - ``name`` with every leading and trailing whitespace character - removed, every internal run of whitespace (spaces, tabs and the - like) collapsed to a single space, and the rest lower-cased. For - example ``"abc def\tghi\tjkl"`` becomes ``"abc def ghi jkl"``. - The result is an empty string when ``name`` holds nothing but - whitespace. - """ - # TODO: реализуйте функцию (используйте своё решение части 3) - return "" + return " ".join(correct_name) # TODO: при необходимости добавьте свои вспомогательные функции def get_storage_str_representation(storage: dict[str, Product]) -> str: - """Render the product store as a text table with data-sized columns. - - The table has the columns named by :data:`TABLE_HEADERS` -- id, name, - price and quantity. Each column is made exactly as wide as the longest - value it carries in this call (its header counted), so the columns - line up when the string is printed to a terminal and no value is ever - truncated. - - Args: - storage: The product store to render. - - Returns: - A multi-line string: a header row, a dashed separator row, then - one row per product in ``storage``, in insertion order. When - ``storage`` is empty only the header and separator rows are - returned, sized to the header labels. - """ - # TODO: реализуйте функцию (используйте своё решение части 3) - return "" + len_headers = [ + len(TABLE_HEADERS[0]), + len(TABLE_HEADERS[1]), + len(TABLE_HEADERS[2]), + len(TABLE_HEADERS[3]), + ] + + for product_id, product_info in storage.items(): + len_id = len(str(product_id)) + len_name = len(str(product_info[NAME_KEY])) + len_price = len(str(product_info[PRICE_KEY])) + len_quantity = len(str(product_info[QUANTITY_KEY])) + + len_headers = [ + max(len_headers[0], len_id), + max(len_headers[1], len_name), + max(len_headers[2], len_price), + max(len_headers[3], len_quantity), + ] + + s = ( + f"| ID {' ' * (len_headers[0] - 2)}| name {' ' * (len_headers[1] - 4)}| price {' ' * (len_headers[2] - 5)}| quantity {' ' * (len_headers[3] - 8)}|\n" + f"|{'-' * (len_headers[0] + 2)}|{'-' * (len_headers[1] + 2)}|{'-' * (len_headers[2] + 2)}|{'-' * (len_headers[3] + 2)}|" + ) + + for product_id, product_info in storage.items(): + s += "\n" + + len_id = len(str(product_id)) + len_name = len(str(product_info[NAME_KEY])) + len_price = len(str(product_info[PRICE_KEY])) + len_quantity = len(str(product_info[QUANTITY_KEY])) + + s += f"| {product_id} {' ' * (len_headers[0] - len_id)}| {product_info[NAME_KEY]} {' ' * (len_headers[1] - len_name)}| {product_info[PRICE_KEY]} {' ' * (len_headers[2] - len_price)}| {product_info[QUANTITY_KEY]} {' ' * (len_headers[3] - len_quantity)}|" + + return s From 8262ef7a5539c6fc9079737ca591a24f08ed01d6 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 27 Oct 2026 22:23:41 +0300 Subject: [PATCH 23/31] crud.py was made --- src/part4/crud.py | 155 ++++++++++++++++++---------------------------- 1 file changed, 60 insertions(+), 95 deletions(-) diff --git a/src/part4/crud.py b/src/part4/crud.py index 471eff00..37eecd93 100644 --- a/src/part4/crud.py +++ b/src/part4/crud.py @@ -23,26 +23,22 @@ than a scan over ``storage.values()``. """ -import uuid # noqa: F401 +import uuid from typing import Any -from .storage import ( # noqa: F401 +from .storage import ( NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product, ) -from .utils import normalize_price, normalize_product_name # noqa: F401 +from .utils import normalize_price, normalize_product_name def generate_product_id() -> str: - """Generate an identifier for a new product. + product_id = uuid.uuid4() - Returns: - A freshly generated UUID, stringified. - """ - # TODO: реализуйте функцию - return "" + return str(product_id) def create_product( @@ -50,46 +46,33 @@ def create_product( product_names: set[str], fields: dict[str, Any], ) -> str | None: - """Add a new product to ``storage`` and return its new identifier. - - Args: - storage: The product store to add to; modified in place on - success. - product_names: The normalised names already in ``storage``; the - new name is added to it in place on success. - fields: A dictionary with the ``name``, ``price`` and ``quantity`` - keys (see :data:`~src.part4.storage.NAME_KEY`, - :data:`~src.part4.storage.PRICE_KEY` and - :data:`~src.part4.storage.QUANTITY_KEY`) describing the - product. ``name`` is normalised (surrounding whitespace - stripped, lower-cased) before it is stored or compared. - ``price`` is a :class:`~decimal.Decimal` amount and is rounded - to the stored money precision before it is saved. - - Returns: - The identifier generated for the new product, or ``None`` when - ``name`` is blank once normalised or a product with the same - normalised name already exists. In the ``None`` case ``storage`` - and ``product_names`` are left unchanged and an explanatory - message is printed. - """ - # TODO: реализуйте функцию - return "" + good_name = normalize_product_name(fields[NAME_KEY]) + if not good_name: + print("product name must not be blank") + return None -def read_product(storage: dict[str, Product], product_id: str) -> Product | None: - """Return the product stored under ``product_id``. + if good_name in product_names: + print(f"product name '{good_name}' is already taken") + return None + + product_id = generate_product_id() - Args: - storage: The product store to search. - product_id: The identifier to look up. + storage[product_id] = { + NAME_KEY: good_name, + PRICE_KEY: normalize_price(fields[PRICE_KEY]), + QUANTITY_KEY: fields[QUANTITY_KEY], + } + product_names.add(good_name) + return product_id - Returns: - The matching product record, or ``None`` when no product carries - that identifier (a message is printed in that case). - """ - # TODO: реализуйте функцию - return {} + +def read_product(storage: dict[str, Product], product_id: str) -> Product | None: + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + return storage[product_id] def update_product( @@ -98,39 +81,30 @@ def update_product( product_id: str, fields: dict[str, Any], ) -> Product | None: - """Overwrite the fields of the product stored under ``product_id``. - - The identifier itself is preserved. ``fields`` may carry any subset of - ``name``, ``price`` and ``quantity``; a key that is missing keeps the - value the product already has, so a caller can update a single field - without repeating the other two. - - Args: - storage: The product store to modify; the matching record is - updated in place on success. - product_names: The normalised names already in ``storage``; on a - successful rename the old name is removed from it and the new - one added. - product_id: The identifier of the product to change. - fields: A dictionary with any of the ``name``, ``price`` and - ``quantity`` keys (see :data:`~src.part4.storage.NAME_KEY`, - :data:`~src.part4.storage.PRICE_KEY` and - :data:`~src.part4.storage.QUANTITY_KEY`) holding the new - values. ``price`` is a :class:`~decimal.Decimal` amount and is - rounded to the stored money precision before it is saved. - Mutated in place: a ``name`` or ``price`` value present in - ``fields`` is overwritten with its normalised form. - - Returns: - The updated product record, or ``None`` when ``name`` is present - and blank once normalised, no product carries that identifier, or - the normalised name is already taken by another product. In every - ``None`` case ``storage`` and ``product_names`` are left unchanged - and an explanatory message is printed. Renaming a product to its - own current name is allowed. - """ - # TODO: реализуйте функцию - return {} + if product_id not in storage: + print(f"no product with id {product_id}") + return None + if NAME_KEY in fields: + fields[NAME_KEY] = normalize_product_name(fields[NAME_KEY]) + if not fields[NAME_KEY]: + print("product name must not be blank") + return None + if ( + storage[product_id][NAME_KEY] != fields[NAME_KEY] + and fields[NAME_KEY] in product_names + ): + print(f"product name '{fields[NAME_KEY]}' is already taken") + return None + if PRICE_KEY in fields: + fields[PRICE_KEY] = normalize_price(fields[PRICE_KEY]) + + if NAME_KEY in fields and fields[NAME_KEY] != storage[product_id][NAME_KEY]: + product_names.remove(storage[product_id][NAME_KEY]) + product_names.add(fields[NAME_KEY]) + + storage[product_id].update(fields) + + return storage[product_id] def delete_product( @@ -138,20 +112,11 @@ def delete_product( product_names: set[str], product_id: str, ) -> str | None: - """Remove the product stored under ``product_id`` from ``storage``. - - Args: - storage: The product store to remove from; modified in place on - success. - product_names: The normalised names already in ``storage``; the - departing product's name is removed from it in place on - success. - product_id: The identifier of the product to remove. - - Returns: - ``product_id`` when a product was removed, or ``None`` when no - product carried that identifier (``storage`` and ``product_names`` - are left unchanged and a message is printed). - """ - # TODO: реализуйте функцию - return "" + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + product_names.remove(storage[product_id][NAME_KEY]) + del storage[product_id] + + return product_id From 8f1c5f2384272ee6eb4888445d1b824ad2e9cfae Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 27 Oct 2026 23:19:05 +0300 Subject: [PATCH 24/31] cart.py and run_admin.py was made --- src/part4/cart.py | 84 +++++++++++++-------------------- src/part4/run_admin.py | 105 ++++++++++++++++++++++++----------------- 2 files changed, 95 insertions(+), 94 deletions(-) diff --git a/src/part4/cart.py b/src/part4/cart.py index aed9bb72..f8410950 100644 --- a/src/part4/cart.py +++ b/src/part4/cart.py @@ -9,7 +9,10 @@ an explanatory message to stdout and returns ``None``. """ -from .storage import Product +from .storage import ( + QUANTITY_KEY, + Product, +) # TODO: при необходимости добавьте свои вспомогательные функции @@ -22,32 +25,22 @@ def add_to_cart( product_id: str, quantity: int, ) -> int | None: - """Move ``quantity`` units of ``product_id`` from the store into ``cart``. + if product_id not in storage: + print(f"no product with id {product_id}") + return None + if quantity > storage[product_id][QUANTITY_KEY]: + print( + f"not enough stock for product {product_id}: {storage[product_id][QUANTITY_KEY]} available, {quantity} requested" + ) + return None - The product is looked up in ``storage``. If it is missing, a message is - printed and nothing changes. If the store holds fewer units than - requested, an explanatory message is printed and nothing changes. - Otherwise the store record is decremented by ``quantity`` and the cart - gains ``quantity`` units of ``product_id`` -- the product is added when - the cart had none of it. + if product_id not in cart: + cart[product_id] = 0 - Args: - storage: The product store to draw stock from; modified in place on - success. - product_names: The normalised names in ``storage``; a - quantity-only change never renames a product, so it is left - unchanged here. - cart: The cart to add the units to; modified in place on success. - product_id: The identifier of the product to add. - quantity: Number of units to move into the cart. + cart[product_id] += quantity + storage[product_id][QUANTITY_KEY] -= quantity - Returns: - The quantity of ``product_id`` in the cart after the addition, or - ``None`` when the product is unknown or the store cannot cover the - request. - """ - # TODO: реализуйте функцию - return 0 + return cart[product_id] def remove_from_cart( @@ -57,31 +50,22 @@ def remove_from_cart( product_id: str, quantity: int, ) -> int | None: - """Move ``quantity`` units of ``product_id`` from ``cart`` back to the store. + if product_id not in cart: + print(f"product {product_id} is not in the cart") + return None + if quantity > cart[product_id]: + print( + f"cart holds only {cart[product_id]} unit(s) of product {product_id}, cannot remove {quantity}" + ) + return None + if product_id not in storage: + print(f"no product with id {product_id}") + return None - If the cart holds no units of ``product_id``, a message is printed and - nothing changes. If it holds fewer units than requested, an explanatory - message is printed and nothing changes. If the product is missing from - ``storage``, a message is printed and nothing changes. Otherwise the cart loses - ``quantity`` units of the product -- the product is dropped from the - cart when its quantity reaches zero -- and the store record gains - ``quantity`` units back. + storage[product_id][QUANTITY_KEY] += quantity + cart[product_id] -= quantity + if cart[product_id] == 0: + del cart[product_id] + return 0 - Args: - storage: The product store to return stock to; modified in place on - success. - product_names: The normalised names in ``storage``; a - quantity-only change never renames a product, so it is left - unchanged here. - cart: The cart to take the units from; modified in place on - success. - product_id: The identifier of the product to remove. - quantity: Number of units to move back into the store. - - Returns: - The quantity of ``product_id`` left in the cart after the removal - (zero means the product was dropped from the cart), or ``None`` when - the cart does not hold the product or holds too few units. - """ - # TODO: реализуйте функцию - return 0 + return cart[product_id] diff --git a/src/part4/run_admin.py b/src/part4/run_admin.py index 2247b29b..74ac5379 100644 --- a/src/part4/run_admin.py +++ b/src/part4/run_admin.py @@ -28,71 +28,88 @@ is left untouched and the loop keeps running; only ``exit`` stops it. """ -from decimal import Decimal, InvalidOperation # noqa: F401 +from decimal import Decimal, InvalidOperation from typing import Final -from .crud import ( # noqa: F401 +from .crud import ( create_product, delete_product, read_product, update_product, ) -from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product # noqa: F401 -from .utils import get_storage_str_representation # noqa: F401 +from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product +from .utils import ( + get_storage_str_representation, +) # TODO: задайте приглашение и текст справки (используйте своё решение части 3) -PROMPT: Final[str] = "" -HELP_TEXT: Final[str] = "" +PROMPT: Final[str] = "admin> " +HELP_TEXT: Final[str] = """Available commands: + help show this message + exit leave the console + show print the whole store as a table + create add a product, print its new id + read print the product with that id + update overwrite that product's fields + delete remove the product with that id +For create and update the price and quantity are the last two words of the +line; everything before them is the product name, so it may contain spaces +(for example "Gibson SG Junior") and needs no quoting.""" -def show_help() -> None: - """Print the command reference to stdout. - The text is the module-level :data:`HELP_TEXT` constant, printed as - is: a heading, one line per command with a short description, and a - note on how multi-word names are parsed. - """ - # TODO: реализуйте функцию (используйте своё решение части 3) +def show_help() -> None: + print(HELP_TEXT) def print_result(result: object) -> None: - """Print a CRUD result to stdout unless it is ``None``. - - Args: - result: The value returned by a CRUD operation. ``None`` means the - operation already reported its own failure, so nothing is - printed in that case. - """ - # TODO: реализуйте функцию (используйте своё решение части 3) + if result is not None: + print(result) def run_command( storage: dict[str, Product], product_names: set[str], line: str ) -> bool: - """Parse one console line and carry out the command it names. - - Args: - storage: The product store shared across the session; mutated in - place by the ``create``, ``update`` and ``delete`` commands. - product_names: The normalised names already in ``storage``; kept - in sync by the ``create``, ``update`` and ``delete`` commands. - line: One line of console input, already stripped of surrounding - whitespace. - - Returns: - ``True`` to keep the read-eval-print loop running, or ``False`` - once the ``exit`` command has been seen. A line that is not a - known command prints a notice and still returns ``True``. - - Raises: - ValueError: If the quantity argument of a CRUD command does not - parse as a base-10 integer. - decimal.InvalidOperation: If the price argument of ``create`` or - ``update`` does not parse as a decimal number. - """ - # TODO: реализуйте функцию - return False + match line.split(): + case ["help"]: + show_help() + return True + case ["exit"]: + return False + case ["show"]: + print(get_storage_str_representation(storage)) + return True + case ["create", *command]: + if len(command) < 3: + print(f"'{line}' is not a command") + return True + quantity = int(command[-1]) + price = Decimal(command[-2]) + name = " ".join(command[:-2]) + fields = {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity} + print_result(create_product(storage, product_names, fields)) + return True + case ["read", id]: + print_result(read_product(storage, id)) + return True + case ["update", id, *command]: + if len(command) < 3: + print(f"'{line}' is not a command") + return True + quantity = int(command[-1]) + price = Decimal(command[-2]) + name = " ".join(command[:-2]) + fields = {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity} + print_result(update_product(storage, product_names, id, fields)) + return True + case ["delete", id]: + answer = delete_product(storage, product_names, id) + print_result(answer) + return True + case _: + print(f"'{line}' is not a command") + return True def main() -> None: From 6df60c5959edfc789785701f5753a6fbebd3cc98 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Mon, 9 Nov 2026 23:48:42 +0300 Subject: [PATCH 25/31] made constants.py --- src/part5/constants.py | 38 ++++++++------------------------------ 1 file changed, 8 insertions(+), 30 deletions(-) diff --git a/src/part5/constants.py b/src/part5/constants.py index 984671bb..afc19ecf 100644 --- a/src/part5/constants.py +++ b/src/part5/constants.py @@ -1,37 +1,15 @@ -"""Bit layout and default epoch for the Twitter Snowflake ID generator. - -A Snowflake identifier is a 63-bit positive integer packed as follows, from -the most significant bit downwards: - - 1 bit unused sign bit, always zero - 41 bits milliseconds elapsed since a custom epoch - 10 bits node identifier - 12 bits per-millisecond sequence counter - -The shift and mask constants should be derived from the bit widths so that -changing a width keeps everything else consistent. -""" - from typing import Final -# TODO: замените заглушки (0) на корректные значения (используйте своё решение -# части 1). - -# Twitter's original Snowflake epoch: 2010-11-04 01:42:54.657 UTC. -EPOCH_MS_DEFAULT: Final[int] = 0 +EPOCH_MS_DEFAULT: Final[int] = 1288834974657 -# Node identifier used when the caller does not supply one. -NODE_ID_DEFAULT: Final[int] = 0 +NODE_ID_DEFAULT: Final[int] = 1 -# Width of each field, in bits. -TIMESTAMP_BITS: Final[int] = 0 -NODE_ID_BITS: Final[int] = 0 -SEQUENCE_ID_BITS: Final[int] = 0 +TIMESTAMP_BITS: Final[int] = 41 +NODE_ID_BITS: Final[int] = 10 +SEQUENCE_ID_BITS: Final[int] = 12 -# Largest value each field can hold. -TIMESTAMP_MS_MAX: Final[int] = 0 -NODE_ID_MAX: Final[int] = 0 -SEQUENCE_ID_MAX: Final[int] = 0 -# Здесь можно добавить собственные вспомогательные константы +TIMESTAMP_MS_MAX: Final[int] = 2**TIMESTAMP_BITS - 1 +NODE_ID_MAX: Final[int] = 2**NODE_ID_BITS - 1 +SEQUENCE_ID_MAX: Final[int] = 2**SEQUENCE_ID_BITS - 1 From 203ee6d7d2aca77d3de4f975f0b9a709fad817bb Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 10 Nov 2026 00:11:40 +0300 Subject: [PATCH 26/31] made snowflake.py --- src/part5/snowflake.py | 128 ++++++++++++++++++----------------------- 1 file changed, 56 insertions(+), 72 deletions(-) diff --git a/src/part5/snowflake.py b/src/part5/snowflake.py index 64e28468..fd470c2d 100644 --- a/src/part5/snowflake.py +++ b/src/part5/snowflake.py @@ -14,99 +14,83 @@ :func:`decode_node_id` and :func:`decode_sequence_id`. """ +import time from collections.abc import Callable -from .constants import EPOCH_MS_DEFAULT, NODE_ID_DEFAULT +from .constants import ( + EPOCH_MS_DEFAULT, + NODE_ID_BITS, + NODE_ID_DEFAULT, + NODE_ID_MAX, + SEQUENCE_ID_BITS, + SEQUENCE_ID_MAX, + TIMESTAMP_MS_MAX, +) def read_current_millis(epoch_ms: int) -> int: - """Read the number of milliseconds elapsed since the custom epoch. + current_time = int(time.time() * 1000) - Args: - epoch_ms: The custom epoch expressed as Unix milliseconds. - - Returns: - The count of whole milliseconds between ``epoch_ms`` and now. Negative - if ``epoch_ms`` lies in the future. - """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + return current_time - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: - """Read the timestamp field out of a Snowflake identifier. - - Args: - snowflake_id: An identifier produced against the same epoch. - epoch_ms: The epoch the identifier was generated against. Defaults to - the original Twitter epoch (2010-11-04 01:42:54.657 UTC). + default_time = snowflake_id >> (NODE_ID_DEFAULT + SEQUENCE_ID_BITS) - Returns: - The absolute Unix time in milliseconds at which the identifier was - generated. - """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + return default_time + epoch_ms def decode_node_id(snowflake_id: int) -> int: - """Read the node identifier field out of a Snowflake identifier. + node_id = (snowflake_id >> 12) & NODE_ID_BITS - Args: - snowflake_id: An identifier produced by a generator from - :func:`get_snowflake_id_generator`. - - Returns: - The node identifier packed into ``snowflake_id``, in the range - ``[0, NODE_ID_MAX]``. - """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + return node_id def decode_sequence_id(snowflake_id: int) -> int: - """Read the sequence counter field out of a Snowflake identifier. - - Args: - snowflake_id: An identifier produced by a generator from - :func:`get_snowflake_id_generator`. + sequence_id = snowflake_id & SEQUENCE_ID_BITS - Returns: - The per-millisecond sequence counter packed into ``snowflake_id``, in - the range ``[0, SEQUENCE_ID_MAX]``. - """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + return sequence_id def get_snowflake_id_generator( node_id: int = NODE_ID_DEFAULT, epoch_ms: int = EPOCH_MS_DEFAULT, ) -> Callable[[], int | None] | None: - """Create a stateful Snowflake identifier generator bound to one node. - - The returned closure remembers the millisecond of its previous call and the - per-millisecond sequence counter, so callers never pass them in. - - Args: - node_id: The identifier of this node, in the range ``[0, NODE_ID_MAX]``. - Optional; defaults to ``NODE_ID_DEFAULT``. - epoch_ms: The start of the epoch as Unix milliseconds. Optional; - defaults to the original Twitter epoch (2010-11-04 01:42:54.657 - UTC). - - Returns: - A zero-argument function ``generate_snowflake_id``. Each call returns a - positive 63-bit integer identifier. It returns ``None`` (after printing - an explanatory message to stdout) if more than ``SEQUENCE_ID_MAX + 1`` - identifiers are requested within one millisecond, or if the elapsed - time no longer fits in the timestamp field (roughly 69 years after - ``epoch_ms``). A failed call does not break the generator: it recovers - once the clock moves on to the next millisecond. - - ``None`` is returned instead of a generator, after printing a message - to stdout, if ``node_id`` is outside ``[0, NODE_ID_MAX]`` or - ``epoch_ms`` lies in the future. - """ - # TODO: реализуйте функцию - return lambda: 0 + if node_id < 0 or node_id > NODE_ID_MAX: + print(f"node_id must be in [0, {NODE_ID_MAX}], got {node_id}") + return None + if read_current_millis(epoch_ms) < 0: + print(f"epoch_ms must not be in the future, got {epoch_ms}") + return None + + last_timestamp_ms = -1 + sequence_id = 0 + + def generate_id() -> int | None: + nonlocal last_timestamp_ms, sequence_id + + current_ms = read_current_millis(epoch_ms) + + if current_ms > TIMESTAMP_MS_MAX: + print(f"timestamp {current_ms} ms overflows {TIMESTAMP_MS_MAX} ms") + return None + + if current_ms == last_timestamp_ms: + sequence_id += 1 + else: + sequence_id = 0 + last_timestamp_ms = current_ms + + if sequence_id > SEQUENCE_ID_MAX: + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], got {sequence_id}") + return None + + snowflake_id = ( + current_ms << (NODE_ID_BITS + SEQUENCE_ID_BITS) + | node_id << SEQUENCE_ID_BITS + | sequence_id + ) + + return snowflake_id + + return generate_id From b8bbb29c8efb25f5942f8c813bc3cf79372e0ecf Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 10 Nov 2026 00:35:44 +0300 Subject: [PATCH 27/31] made decorators.py --- src/part5/decorators.py | 53 +++++++++++++++++++---------------------- 1 file changed, 25 insertions(+), 28 deletions(-) diff --git a/src/part5/decorators.py b/src/part5/decorators.py index 21a9f237..15e49a1c 100644 --- a/src/part5/decorators.py +++ b/src/part5/decorators.py @@ -14,12 +14,13 @@ """ from collections.abc import Callable +from functools import wraps from typing import Final # TODO: задайте имена двух счётчиков, см. TASK.md -SUCCESS_KEY: Final[str] = "" -FAILS_KEY: Final[str] = "" +SUCCESS_KEY: Final[str] = "success" +FAILS_KEY: Final[str] = "fails" type Stats = dict[str, int] @@ -29,29 +30,25 @@ def collect_stats[**P, R]( key: str, registry: Registry ) -> Callable[[Callable[P, R | None]], Callable[P, R | None]]: - """Build a decorator that counts successful and failed calls of a function. - - Decorating registers a fresh record ``{"success": 0, "fails": 0}`` in - ``registry`` under ``key``. Every call of the decorated function then - updates that record in place: a call that returns ``None`` adds one to the - failure counter, any other result adds one to the success counter. The - result is passed through unchanged, and a call that raises an exception - is not counted at all. - - If ``key`` is already in ``registry``, a message is printed, the existing - record is left untouched and the function is returned undecorated, so its - calls never mix into the counters of whoever registered the key first. - - Args: - key: The registry key to keep this function's counters under, for - example the name of the console command it implements. - registry: The dictionary that receives the counters; modified in - place when the function is decorated and on every later call. - - Returns: - A decorator for a function whose result is either some value or - ``None``. The decorated function has the same signature, name and - docstring as the original (see :func:`functools.wraps`). - """ - # TODO: реализуйте декоратор - return lambda function: function + + def decorator(function): + if key in registry: + print(f"stats key {key!r} is already registered") + return function + registry[key] = {SUCCESS_KEY: 0, FAILS_KEY: 0} + + @wraps(function) + def wrapper(*args, **kwargs): + + result = function(*args, **kwargs) + + if result is None: + registry[key][FAILS_KEY] += 1 + else: + registry[key][SUCCESS_KEY] += 1 + + return result + + return wrapper + + return decorator From 2dbb7e277207bb41cf374a045dfce27d7811b972 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 10 Nov 2026 13:19:52 +0300 Subject: [PATCH 28/31] made crud.py --- src/part5/crud.py | 196 ++++++++++++++++++---------------------------- 1 file changed, 78 insertions(+), 118 deletions(-) diff --git a/src/part5/crud.py b/src/part5/crud.py index 243b0528..c9231478 100644 --- a/src/part5/crud.py +++ b/src/part5/crud.py @@ -38,154 +38,114 @@ from collections.abc import Callable from typing import Any, Final -from .decorators import Registry -from .storage import Product +from .decorators import Registry, collect_stats +from .snowflake import get_snowflake_id_generator +from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product +from .utils import normalize_price, normalize_product_name STATS_REGISTRY: Final[Registry] = {} # TODO: задайте ключи операций в реестре, см. TASK.md -CREATE_KEY: Final[str] = "" -READ_KEY: Final[str] = "" -UPDATE_KEY: Final[str] = "" -DELETE_KEY: Final[str] = "" +CREATE_KEY: Final[str] = "create" +READ_KEY: Final[str] = "read" +UPDATE_KEY: Final[str] = "update" +DELETE_KEY: Final[str] = "delete" -# TODO: при необходимости заведите здесь общий генератор Snowflake-идентификаторов -# для generate_snowflake_id (см. TASK.md) +SNOWFLAKE_GENERATOR = get_snowflake_id_generator() -def generate_snowflake_id() -> int | None: - """Issue the next product identifier from the shared Snowflake generator. - This is the identifier source callers pass to :func:`create_product`. +def generate_snowflake_id() -> int | None: + if SNOWFLAKE_GENERATOR is None: + return None - Returns: - A positive 63-bit Snowflake integer, or ``None`` (after a message - has been printed) when no identifier can be issued right now -- see - :func:`~src.part5.snowflake.get_snowflake_id_generator` for the - cases. - """ - # TODO: реализуйте функцию - return 0 + return SNOWFLAKE_GENERATOR() -# TODO: оберните операцию декоратором collect_stats +@collect_stats(CREATE_KEY, STATS_REGISTRY) def create_product( storage: dict[int, Product], product_names: set[str], fields: dict[str, Any], generate_id: Callable[[], int | None], ) -> int | None: - """Add a new product to ``storage`` and return its new identifier. - - Args: - storage: The product store to add to; modified in place on - success. - product_names: The normalised names already in ``storage``; the - new name is added to it in place on success. - fields: A dictionary with the ``name``, ``price`` and ``quantity`` - keys (see :data:`~src.part5.storage.NAME_KEY`, - :data:`~src.part5.storage.PRICE_KEY` and - :data:`~src.part5.storage.QUANTITY_KEY`) describing the - product. ``name`` is normalised (surrounding whitespace - stripped, lower-cased) before it is stored or compared. - ``price`` is a :class:`~decimal.Decimal` amount and is rounded - to the stored money precision before it is saved. - generate_id: A zero-argument function returning the identifier for - the new product, or ``None`` if it cannot issue one (for - example :func:`generate_snowflake_id`). It is only expected to - return an identifier that is not yet a key of ``storage``. - - Returns: - The identifier returned by ``generate_id`` for the new product, or - ``None`` when ``name`` is blank once normalised, a product with - the same normalised name already exists, or ``generate_id`` - returned ``None``. In the ``None`` case ``storage`` and - ``product_names`` are left unchanged and an explanatory message is - printed (for the last case, by ``generate_id`` itself). - """ - # TODO: реализуйте функцию - return 0 - - -# TODO: оберните операцию декоратором collect_stats -def read_product(storage: dict[int, Product], product_id: int) -> Product | None: - """Return the product stored under ``product_id``. + good_name = normalize_product_name(fields[NAME_KEY]) - Args: - storage: The product store to search. - product_id: The identifier to look up. + if not good_name: + print("product name must not be blank") + return None - Returns: - The matching product record, or ``None`` when no product carries - that identifier (a message is printed in that case). - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return {} + if good_name in product_names: + print(f"product name '{good_name}' is already taken") + return None + product_id = generate_id() + if product_id is None: + return None -# TODO: оберните операцию декоратором collect_stats + storage[product_id] = { + NAME_KEY: good_name, + PRICE_KEY: normalize_price(fields[PRICE_KEY]), + QUANTITY_KEY: fields[QUANTITY_KEY], + } + product_names.add(good_name) + return product_id + + +@collect_stats(READ_KEY, STATS_REGISTRY) +def read_product(storage: dict[int, Product], product_id: int) -> Product | None: + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + return storage[product_id] + + +@collect_stats(UPDATE_KEY, STATS_REGISTRY) def update_product( storage: dict[int, Product], product_names: set[str], product_id: int, fields: dict[str, Any], ) -> Product | None: - """Overwrite the fields of the product stored under ``product_id``. - - The identifier itself is preserved. ``fields`` may carry any subset of - ``name``, ``price`` and ``quantity``; a key that is missing keeps the - value the product already has, so a caller can update a single field - without repeating the other two. - - Args: - storage: The product store to modify; the matching record is - updated in place on success. - product_names: The normalised names already in ``storage``; on a - successful rename the old name is removed from it and the new - one added. - product_id: The identifier of the product to change. - fields: A dictionary with any of the ``name``, ``price`` and - ``quantity`` keys (see :data:`~src.part5.storage.NAME_KEY`, - :data:`~src.part5.storage.PRICE_KEY` and - :data:`~src.part5.storage.QUANTITY_KEY`) holding the new - values. ``price`` is a :class:`~decimal.Decimal` amount and is - rounded to the stored money precision before it is saved. - Mutated in place: a ``name`` or ``price`` value present in - ``fields`` is overwritten with its normalised form. - - Returns: - The updated product record, or ``None`` when ``name`` is present - and blank once normalised, no product carries that identifier, or - the normalised name is already taken by another product. In every - ``None`` case ``storage`` and ``product_names`` are left unchanged - and an explanatory message is printed. Renaming a product to its - own current name is allowed. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return {} - - -# TODO: оберните операцию декоратором collect_stats + if product_id not in storage: + print(f"no product with id {product_id}") + return None + if NAME_KEY in fields: + fields[NAME_KEY] = normalize_product_name(fields[NAME_KEY]) + if not fields[NAME_KEY]: + print("product name must not be blank") + return None + if ( + storage[product_id][NAME_KEY] != fields[NAME_KEY] + and fields[NAME_KEY] in product_names + ): + print(f"product name '{fields[NAME_KEY]}' is already taken") + return None + if PRICE_KEY in fields: + fields[PRICE_KEY] = normalize_price(fields[PRICE_KEY]) + + if NAME_KEY in fields and fields[NAME_KEY] != storage[product_id][NAME_KEY]: + product_names.remove(storage[product_id][NAME_KEY]) + product_names.add(fields[NAME_KEY]) + + storage[product_id].update(fields) + + return storage[product_id] + + +@collect_stats(DELETE_KEY, STATS_REGISTRY) def delete_product( storage: dict[int, Product], product_names: set[str], product_id: int, ) -> int | None: - """Remove the product stored under ``product_id`` from ``storage``. - - Args: - storage: The product store to remove from; modified in place on - success. - product_names: The normalised names already in ``storage``; the - departing product's name is removed from it in place on - success. - product_id: The identifier of the product to remove. - - Returns: - ``product_id`` when a product was removed, or ``None`` when no - product carried that identifier (``storage`` and ``product_names`` - are left unchanged and a message is printed). - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return 0 + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + product_names.remove(storage[product_id][NAME_KEY]) + del storage[product_id] + + return product_id From dfd71c9e5583efc775ca13045bcbf00be91d1251 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 10 Nov 2026 18:01:20 +0300 Subject: [PATCH 29/31] made cart.py --- src/part5/cart.py | 82 ++++++++++++++++++----------------------------- 1 file changed, 31 insertions(+), 51 deletions(-) diff --git a/src/part5/cart.py b/src/part5/cart.py index a2363b3a..e1de6ab9 100644 --- a/src/part5/cart.py +++ b/src/part5/cart.py @@ -9,7 +9,7 @@ an explanatory message to stdout and returns ``None``. """ -from .storage import Product +from .storage import QUANTITY_KEY, Product # TODO: при необходимости добавьте свои вспомогательные функции @@ -22,33 +22,22 @@ def add_to_cart( product_id: int, quantity: int, ) -> int | None: - """Move ``quantity`` units of ``product_id`` from the store into ``cart``. + if product_id not in storage: + print(f"no product with id {product_id}") + return None + if quantity > storage[product_id][QUANTITY_KEY]: + print( + f"not enough stock for product {product_id}: {storage[product_id][QUANTITY_KEY]} available, {quantity} requested" + ) + return None - The product is looked up in ``storage``. If it is missing, a message is - printed (by :func:`~src.part5.crud.read_product`) and nothing - changes. If the store holds fewer units than requested, an explanatory - message is printed and nothing changes. Otherwise the store record is - decremented by ``quantity`` and the cart gains ``quantity`` units of - ``product_id`` -- the product is added when the cart had none of it. + if product_id not in cart: + cart[product_id] = 0 - Args: - storage: The product store to draw stock from; modified in place on - success. - product_names: The normalised names in ``storage``; threaded - through to :func:`~src.part5.crud.update_product`, which - keeps it in sync (a quantity-only update never renames a - product, so it is left unchanged here). - cart: The cart to add the units to; modified in place on success. - product_id: The identifier of the product to add. - quantity: Number of units to move into the cart. + cart[product_id] += quantity + storage[product_id][QUANTITY_KEY] -= quantity - Returns: - The quantity of ``product_id`` in the cart after the addition, or - ``None`` when the product is unknown or the store cannot cover the - request. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return 0 + return cart[product_id] def remove_from_cart( @@ -58,31 +47,22 @@ def remove_from_cart( product_id: int, quantity: int, ) -> int | None: - """Move ``quantity`` units of ``product_id`` from ``cart`` back to the store. + if product_id not in cart: + print(f"product {product_id} is not in the cart") + return None + if quantity > cart[product_id]: + print( + f"cart holds only {cart[product_id]} unit(s) of product {product_id}, cannot remove {quantity}" + ) + return None + if product_id not in storage: + print(f"no product with id {product_id}") + return None - If the cart holds no units of ``product_id``, a message is printed and - nothing changes. If it holds fewer units than requested, an explanatory - message is printed and nothing changes. Otherwise the cart loses - ``quantity`` units of the product -- the product is dropped from the - cart when its quantity reaches zero -- and the store record gains - ``quantity`` units back. + storage[product_id][QUANTITY_KEY] += quantity + cart[product_id] -= quantity + if cart[product_id] == 0: + del cart[product_id] + return 0 - Args: - storage: The product store to return stock to; modified in place on - success. - product_names: The normalised names in ``storage``; threaded - through to :func:`~src.part5.crud.update_product`, which - keeps it in sync (a quantity-only update never renames a - product, so it is left unchanged here). - cart: The cart to take the units from; modified in place on - success. - product_id: The identifier of the product to remove. - quantity: Number of units to move back into the store. - - Returns: - The quantity of ``product_id`` left in the cart after the removal - (zero means the product was dropped from the cart), or ``None`` when - the cart does not hold the product or holds too few units. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return 0 + return cart[product_id] From 2673abe81308375d3543ad125529511487e5cad4 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 10 Nov 2026 18:31:21 +0300 Subject: [PATCH 30/31] made utils.py --- src/part5/utils.py | 187 +++++++++++++++++++++++++++++---------------- 1 file changed, 120 insertions(+), 67 deletions(-) diff --git a/src/part5/utils.py b/src/part5/utils.py index b2ad4dc4..6d5b940d 100644 --- a/src/part5/utils.py +++ b/src/part5/utils.py @@ -21,100 +21,153 @@ look, with the success rate of every command as a percentage. """ -from decimal import Decimal +from decimal import ROUND_HALF_UP, Decimal from typing import Final -from .decorators import Registry -from .storage import Product +from .decorators import FAILS_KEY, SUCCESS_KEY, Registry +from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product # TODO: задайте число знаков после запятой и шаг квантования (используйте своё # решение части 4) -PRICE_PRECISION: Final[int] = 0 -PRICE_STEP: Final = Decimal(0) +PRICE_PRECISION: Final[int] = 2 +PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) # TODO: задайте заголовки столбцов таблицы (используйте своё решение части 4) -TABLE_HEADERS: Final[tuple[str, ...]] = () +TABLE_HEADERS: Final[tuple[str, ...]] = ("ID", "name", "price", "quantity") # TODO: задайте заголовки столбцов таблицы статистики, см. TASK.md -STATS_TABLE_HEADERS: Final[tuple[str, ...]] = () +STATS_TABLE_HEADERS: Final[tuple[str, ...]] = ( + "command name", + "success", + "fails", + "success rate", +) def normalize_price(price: Decimal) -> Decimal: - """Round a price to the precision every stored record uses. + correct_price = price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) - Args: - price: The raw price amount. - - Returns: - ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, - with halves rounded up. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return Decimal(0) + return correct_price def normalize_product_name(name: str) -> str: - """Reduce a product name to the canonical form the store keeps. - - Args: - name: The raw product name. + correct_name = [word.lower() for word in name.split()] - Returns: - ``name`` with every leading and trailing whitespace character - removed, every internal run of whitespace (spaces, tabs and the - like) collapsed to a single space, and the rest lower-cased. For - example ``"abc def\tghi\tjkl"`` becomes ``"abc def ghi jkl"``. - The result is an empty string when ``name`` holds nothing but - whitespace. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return "" + return " ".join(correct_name) # TODO: при необходимости добавьте свои вспомогательные функции def get_storage_str_representation(storage: dict[int, Product]) -> str: - """Render the product store as a text table with data-sized columns. + len_headers = [ + len(TABLE_HEADERS[0]), + len(TABLE_HEADERS[1]), + len(TABLE_HEADERS[2]), + len(TABLE_HEADERS[3]), + ] + + for product_id, product_info in storage.items(): + len_id = len(str(product_id)) + len_name = len(str(product_info[NAME_KEY])) + len_price = len(str(product_info[PRICE_KEY])) + len_quantity = len(str(product_info[QUANTITY_KEY])) + + len_headers = [ + max(len_headers[0], len_id), + max(len_headers[1], len_name), + max(len_headers[2], len_price), + max(len_headers[3], len_quantity), + ] + + first_header = [f" {TABLE_HEADERS[i].ljust(len_headers[i])} " for i in range(4)] + + first_row = "|" + "|".join(first_header) + "|" + + sep_str = ["-" * (len_headers[i] + 2) for i in range(4)] + sep_row = "|" + "|".join(sep_str) + "|" + + strings = [first_row, sep_row] - The table has the columns named by :data:`TABLE_HEADERS` -- id, name, - price and quantity. Each column is made exactly as wide as the longest - value it carries in this call (its header counted), so the columns - line up when the string is printed to a terminal and no value is ever - truncated. + for product_id, product_info in storage.items(): + current_info = [ + str(product_id), + str(product_info[NAME_KEY]), + str(product_info[PRICE_KEY]), + str(product_info[QUANTITY_KEY]), + ] - Args: - storage: The product store to render. + current_string = [ + f" {current_info[i].ljust(len_headers[i])} " for i in range(4) + ] + current_string_with_sep = "|" + "|".join(current_string) + "|" + strings.append(current_string_with_sep) - Returns: - A multi-line string: a header row, a dashed separator row, then - one row per product in ``storage``, in insertion order. When - ``storage`` is empty only the header and separator rows are - returned, sized to the header labels. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return "" + return "\n".join(strings) def get_stats_str_representation(registry: Registry) -> str: - """Render the call statistics as a text table with data-sized columns. - - The table has the columns named by :data:`STATS_TABLE_HEADERS` -- command - name, number of successful calls, number of failed calls and success - rate. It is laid out like the one from - :func:`get_storage_str_representation`: every column is as wide as the - longest value it carries, its header counted. - - Args: - registry: The statistics to render, a mapping of command name to the - counters kept by :func:`~src.part5.decorators.collect_stats`. - - Returns: - A multi-line string: a header row, a dashed separator row, then one - row per registry entry in insertion order. When ``registry`` is - empty only the header and separator rows are returned, sized to the - header labels. - """ - # TODO: реализуйте функцию - return "" + len_headers = [ + len(STATS_TABLE_HEADERS[0]), + len(STATS_TABLE_HEADERS[1]), + len(STATS_TABLE_HEADERS[2]), + len(STATS_TABLE_HEADERS[3]), + ] + + for command_name, stats in registry.items(): + success = stats[SUCCESS_KEY] + fails = stats[FAILS_KEY] + total = success + fails + + if total == 0: + rate_str = "0.00%" + else: + rate_str = f"{(success / total * 100):.2f}%" + + len_cmd = len(command_name) + len_success = len(str(success)) + len_fails = len(str(fails)) + len_rate = len(rate_str) + + len_headers = [ + max(len_headers[0], len_cmd), + max(len_headers[1], len_success), + max(len_headers[2], len_fails), + max(len_headers[3], len_rate), + ] + + first_header = [ + f" {STATS_TABLE_HEADERS[i].ljust(len_headers[i])} " for i in range(4) + ] + first_row = "|" + "|".join(first_header) + "|" + + sep_str = ["-" * (len_headers[i] + 2) for i in range(4)] + sep_row = "|" + "|".join(sep_str) + "|" + + strings = [first_row, sep_row] + + for command_name, stats in registry.items(): + success = stats[SUCCESS_KEY] + fails = stats[FAILS_KEY] + total = success + fails + + if total == 0: + rate_str = "0.00%" + else: + rate_str = f"{(success / total * 100):.2f}%" + + current_info = [ + command_name, + str(success), + str(fails), + rate_str, + ] + + current_string = [ + f" {current_info[i].ljust(len_headers[i])} " for i in range(4) + ] + current_string_with_sep = "|" + "|".join(current_string) + "|" + strings.append(current_string_with_sep) + + return "\n".join(strings) From e8da1b5e5b2f5cc69b5bd75b0b0c7af7506daca3 Mon Sep 17 00:00:00 2001 From: Roman Shkryl Date: Tue, 10 Nov 2026 18:59:25 +0300 Subject: [PATCH 31/31] made run_admin.py --- src/part5/run_admin.py | 113 ++++++++++++++++++++++++++--------------- 1 file changed, 71 insertions(+), 42 deletions(-) diff --git a/src/part5/run_admin.py b/src/part5/run_admin.py index d2e83947..ed8ae495 100644 --- a/src/part5/run_admin.py +++ b/src/part5/run_admin.py @@ -36,65 +36,94 @@ is left untouched and the loop keeps running; only ``exit`` stops it. """ -from decimal import InvalidOperation +from decimal import Decimal, InvalidOperation from typing import Final -from .storage import Product +from .crud import ( + STATS_REGISTRY, + create_product, + delete_product, + generate_snowflake_id, + read_product, + update_product, +) +from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product +from .utils import ( + get_stats_str_representation, + get_storage_str_representation, +) # TODO: задайте приглашение и текст справки (используйте своё решение части 4, # не забудьте добавить команду stats, см. TASK.md) -PROMPT: Final[str] = "" -HELP_TEXT: Final[str] = "" +PROMPT: Final[str] = "admin> " +HELP_TEXT: Final[str] = """Available commands: + help show this message + exit leave the console + show print the whole store as a table + create add a product, print its new id + read print the product with that id + update overwrite that product's fields + delete remove the product with that id + stats print call statistics of the CRUD commands + +For create and update the price and quantity are the last two words of the +line; everything before them is the product name, so it may contain spaces +(for example "Gibson SG Junior") and needs no quoting.""" def show_help() -> None: - """Print the command reference to stdout. - - The text is the module-level :data:`HELP_TEXT` constant, printed as - is: a heading, one line per command with a short description, and a - note on how multi-word names are parsed. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) + print(HELP_TEXT) def print_result(result: object) -> None: - """Print a CRUD result to stdout unless it is ``None``. - - Args: - result: The value returned by a CRUD operation. ``None`` means the - operation already reported its own failure, so nothing is - printed in that case. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) + if result is not None: + print(result) def run_command( storage: dict[int, Product], product_names: set[str], line: str ) -> bool: - """Parse one console line and carry out the command it names. - - Args: - storage: The product store shared across the session; mutated in - place by the ``create``, ``update`` and ``delete`` commands. - product_names: The normalised names already in ``storage``; kept - in sync by the ``create``, ``update`` and ``delete`` commands. - line: One line of console input, already stripped of surrounding - whitespace. - - Returns: - ``True`` to keep the read-eval-print loop running, or ``False`` - once the ``exit`` command has been seen. A line that is not a - known command prints a notice and still returns ``True``. - - Raises: - ValueError: If the id or quantity argument of a CRUD command does - not parse as a base-10 integer. - decimal.InvalidOperation: If the price argument of ``create`` or - ``update`` does not parse as a decimal number. - """ - # TODO: реализуйте функцию - return False + match line.split(): + case ["help"]: + show_help() + case ["exit"]: + return False + case ["show"]: + print(get_storage_str_representation(storage)) + case ["create", *name_parts, price_str, quantity_str]: + quantity = int(quantity_str) + price = Decimal(price_str) + name = " ".join(name_parts) + fields = {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity} + print_result( + create_product(storage, product_names, fields, generate_snowflake_id) + ) + + case ["read", id_str]: + id_int = int(id_str) + print_result(read_product(storage, id_int)) + + case ["update", id_str, *name_parts, price_str, quantity_str]: + id_int = int(id_str) + quantity = int(quantity_str) + price = Decimal(price_str) + name = " ".join(name_parts) + fields = {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity} + + print_result(update_product(storage, product_names, id_int, fields)) + case ["delete", id_str]: + id_int = int(id_str) + answer = delete_product(storage, product_names, id_int) + print_result(answer) + + case ["stats"]: + print(get_stats_str_representation(STATS_REGISTRY)) + + case _: + print(f"'{line}' is not a command") + + return True def main() -> None: