From 7d3b05a7373540d467038429328b758495fb551a Mon Sep 17 00:00:00 2001 From: Lenovo Date: Fri, 25 Sep 2026 19:33:03 +0300 Subject: [PATCH 1/4] Solve task 1 --- src/part1/constants.py | 23 +++++------ src/part1/snowflake.py | 39 +++++++++++++------ ...t1snowflake.py\357\200\27216\357\200\2721" | 0 3 files changed, 36 insertions(+), 26 deletions(-) create mode 100644 "srcpart1snowflake.py\357\200\27216\357\200\2721" diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..0d52b967 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -15,24 +15,19 @@ 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 +TIMESTAMP_SHIFT: Final[int] = SEQUENCE_ID_BITS + NODE_ID_BITS # 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 -# (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 d3abf050..29fee069 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -13,14 +13,16 @@ :func:`decode_node_id` and :func:`decode_sequence_id`. """ -import time # noqa: F401 +import time -from .constants import ( # noqa: F401 +from .constants import ( EPOCH_MS_DEFAULT, NODE_ID_DEFAULT, NODE_ID_MAX, + SEQUENCE_ID_BITS, SEQUENCE_ID_MAX, TIMESTAMP_MS_MAX, + TIMESTAMP_SHIFT, ) @@ -34,8 +36,8 @@ def read_current_millis(epoch_ms: int) -> int: 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 int(time.time() * 1000) - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: @@ -50,8 +52,8 @@ def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> The absolute Unix time in milliseconds at which the identifier was generated. """ - # TODO: реализуйте функцию - return 0 + + return (snowflake_id >> TIMESTAMP_SHIFT) + epoch_ms def decode_node_id(snowflake_id: int) -> int: @@ -64,8 +66,8 @@ def decode_node_id(snowflake_id: int) -> int: The node identifier packed into ``snowflake_id``, in the range ``[0, NODE_ID_MAX]``. """ - # TODO: реализуйте функцию - return 0 + + return (snowflake_id >> SEQUENCE_ID_BITS) & NODE_ID_MAX def decode_sequence_id(snowflake_id: int) -> int: @@ -78,8 +80,8 @@ def decode_sequence_id(snowflake_id: int) -> int: The per-millisecond sequence counter packed into ``snowflake_id``, in the range ``[0, SEQUENCE_ID_MAX]``. """ - # TODO: реализуйте функцию - return 0 + + return snowflake_id & SEQUENCE_ID_MAX def generate_snowflake_id( @@ -110,5 +112,18 @@ def generate_snowflake_id( 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 not 0 <= node_id <= NODE_ID_MAX: + print(f"node_id must be in [0, {NODE_ID_MAX}], got {node_id}") + return None + + if not 0 <= sequence_id <= SEQUENCE_ID_MAX: + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], got {sequence_id}") + return None + + elapsed_ms = read_current_millis(epoch_ms) + if elapsed_ms > TIMESTAMP_MS_MAX: + print("timestamp overflows") + return None + + return (elapsed_ms << TIMESTAMP_SHIFT) | (node_id << SEQUENCE_ID_BITS) | sequence_id diff --git "a/srcpart1snowflake.py\357\200\27216\357\200\2721" "b/srcpart1snowflake.py\357\200\27216\357\200\2721" new file mode 100644 index 00000000..e69de29b From 8bce25d9dc217bb2e271401498fa16f47856ff21 Mon Sep 17 00:00:00 2001 From: Lenovo Date: Fri, 2 Oct 2026 23:17:50 +0300 Subject: [PATCH 2/4] Solve task 2 --- src/part2/cart.py | 81 +++++++++++++++++++++++++++++++++++++++----- src/part2/crud.py | 62 ++++++++++++++++++++++++++------- src/part2/storage.py | 10 +++--- src/part2/utils.py | 11 +++--- 4 files changed, 132 insertions(+), 32 deletions(-) diff --git a/src/part2/cart.py b/src/part2/cart.py index 063f9aea..58a3d128 100644 --- a/src/part2/cart.py +++ b/src/part2/cart.py @@ -11,8 +11,8 @@ 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, @@ -22,9 +22,16 @@ type CartLine = tuple[int, int] -# TODO: задайте позиции полей внутри кортежа CartLine + LINE_PRODUCT_ID_INDEX: Final = 0 -LINE_QUANTITY_INDEX: Final = 0 +LINE_QUANTITY_INDEX: Final = 1 + + +def find_cart_index(cart: list[CartLine], product_id: int) -> int | None: + for index, line in enumerate(cart): + if line[LINE_PRODUCT_ID_INDEX] == product_id: + return index + return None def add_to_cart( @@ -53,8 +60,33 @@ def add_to_cart( 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 + + stock_quantity = product[QUANTITY_INDEX] + if stock_quantity < quantity: + print( + f"not enough stock for product {product_id}: " + f"{stock_quantity} available, {quantity} requested" + ) + return None + + update_product( + storage, + product_id, + (product[NAME_INDEX], product[PRICE_INDEX], stock_quantity - quantity), + ) + + line_index = find_cart_index(cart, product_id) + if line_index is None: + new_line = (product_id, quantity) + cart.append(new_line) + return new_line + + update_line = (product_id, cart[line_index][LINE_QUANTITY_INDEX] + quantity) + cart[line_index] = update_line + return update_line def remove_from_cart( @@ -85,5 +117,38 @@ def remove_from_cart( 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) + line_index = find_cart_index(cart, product_id) + if line_index is None: + print(f"product {product_id} is not in the cart") + return None + + in_cart = cart[line_index][LINE_QUANTITY_INDEX] + if in_cart < quantity: + print( + f"cart holds only {in_cart} unit(s) of product " + f"{product_id}, cannot remove {quantity}" + ) + return None + + product = read_product(storage, product_id) + if product is None: + return None + + update_product( + storage, + product_id, + ( + product[NAME_INDEX], + product[PRICE_INDEX], + product[QUANTITY_INDEX] + quantity, + ), + ) + + new_quantity = in_cart - quantity + if new_quantity == 0: + cart.pop(line_index) + return (product_id, 0) + + updated_line = (product_id, new_quantity) + cart[line_index] = updated_line + return updated_line diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..ca598461 100644 --- a/src/part2/crud.py +++ b/src/part2/crud.py @@ -14,13 +14,20 @@ 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 find_product_index(storage: list[Product], product_id: int) -> int | None: + for index, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + return index + return None def generate_product_id(storage: list[Product]) -> int: @@ -34,8 +41,11 @@ def generate_product_id(storage: list[Product]) -> int: :data:`~src.part2.storage.PRODUCT_ID_MIN` when ``storage`` is empty. """ - # TODO: реализуйте функцию - return 0 + + if not storage: + return PRODUCT_ID_MIN + + return max(product[PRODUCT_ID_INDEX] for product in storage) + 1 def create_product( @@ -56,8 +66,18 @@ def create_product( ``storage`` is left unchanged and a message naming the clashing name is printed. """ - # TODO: реализуйте функцию - return 0 + + name, price, quantity = fields + for product in storage: + if product[NAME_INDEX] == name: + print(f"product name '{name}' is already taken") + return None + + new_id = generate_product_id(storage) + new_product = (new_id, name, normalize_price(price), quantity) + storage.append(new_product) + + return new_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -72,8 +92,12 @@ def read_product(storage: list[Product], product_id: int) -> Product | None: ``None`` when no product carries that identifier (a message is printed in that case). """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + + index = find_product_index(storage, product_id) + if index is None: + print(f"no product with id {product_id}") + return None + return storage[index] def update_product( @@ -99,8 +123,16 @@ def update_product( ``None`` when no product carries that identifier (``storage`` is left unchanged and a message is printed). """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + + name, price, quantity = fields + index = find_product_index(storage, product_id) + if index is None: + print(f"no product with id {product_id}") + return None + + updated_product = (product_id, name, normalize_price(price), quantity) + storage[index] = updated_product + return updated_product def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -116,5 +148,11 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: product carried that identifier (``storage`` is left unchanged and a message is printed). """ - # TODO: реализуйте функцию - return 0 + + index = find_product_index(storage, product_id) + if index is None: + print(f"no product with id {product_id}") + return None + + storage.pop(index) + return product_id diff --git a/src/part2/storage.py b/src/part2/storage.py index b63d5fc7..e4bceff1 100644 --- a/src/part2/storage.py +++ b/src/part2/storage.py @@ -24,11 +24,9 @@ type Product = tuple[int, str, Decimal, int] -# 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 diff --git a/src/part2/utils.py b/src/part2/utils.py index ec0348d3..fa159f32 100644 --- a/src/part2/utils.py +++ b/src/part2/utils.py @@ -6,13 +6,12 @@ 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] = 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: @@ -25,5 +24,5 @@ def normalize_price(price: Decimal) -> Decimal: ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, with halves rounded up. """ - # TODO: реализуйте функцию - return Decimal(0) + + return price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) From 88bbe07c055f2d016d5dd2698dfda7da121abb20 Mon Sep 17 00:00:00 2001 From: Lenovo Date: Mon, 12 Oct 2026 22:40:41 +0300 Subject: [PATCH 3/4] Solve task 3 --- src/part2/cart.py | 6 +--- src/part3/TASK.md | 2 +- src/part3/crud.py | 77 +++++++++++++++++++++++++++++++++++------- src/part3/run_admin.py | 69 +++++++++++++++++++++++++++++++------ src/part3/storage.py | 12 +++---- src/part3/utils.py | 59 ++++++++++++++++++++++++-------- 6 files changed, 175 insertions(+), 50 deletions(-) diff --git a/src/part2/cart.py b/src/part2/cart.py index 58a3d128..e4b6c3f6 100644 --- a/src/part2/cart.py +++ b/src/part2/cart.py @@ -137,11 +137,7 @@ def remove_from_cart( update_product( storage, product_id, - ( - product[NAME_INDEX], - product[PRICE_INDEX], - product[QUANTITY_INDEX] + quantity, - ), + (product[NAME_INDEX], product[PRICE_INDEX], product[QUANTITY_INDEX] + quantity), ) new_quantity = in_cart - quantity diff --git a/src/part3/TASK.md b/src/part3/TASK.md index e48ecdac..a8c567b7 100644 --- a/src/part3/TASK.md +++ b/src/part3/TASK.md @@ -1,4 +1,4 @@ -# Задача: нормализация имён, печать хранилища таблицей и админ-консоль + # Задача: нормализация имён, печать хранилища таблицей и админ-консоль ## Легенда diff --git a/src/part3/crud.py b/src/part3/crud.py index 68811d7e..b928f250 100644 --- a/src/part3/crud.py +++ b/src/part3/crud.py @@ -20,13 +20,20 @@ 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 find_product_index(storage: list[Product], product_id: int) -> int | None: + for index, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + return index + return None def generate_product_id(storage: list[Product]) -> int: @@ -40,8 +47,10 @@ def generate_product_id(storage: list[Product]) -> int: :data:`~src.part3.storage.PRODUCT_ID_MIN` when ``storage`` is empty. """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return 0 + + if not storage: + return PRODUCT_ID_MIN + return max(product[PRODUCT_ID_INDEX] for product in storage) + 1 def create_product( @@ -64,8 +73,24 @@ def create_product( normalised name already exists. In the ``None`` case ``storage`` is left unchanged and an explanatory message is printed. """ - # TODO: реализуйте функцию - return 0 + + name, price, quantity = fields + norm_name = normalize_product_name(name) + + if not norm_name: + print("product name must not be blank") + return None + + for product in storage: + if product[NAME_INDEX] == norm_name: + print(f"product name '{norm_name}' is already taken") + return None + + new_id = generate_product_id(storage) + new_product = (new_id, norm_name, normalize_price(price), quantity) + storage.append(new_product) + + return new_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -80,8 +105,11 @@ def read_product(storage: list[Product], product_id: int) -> Product | None: ``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) + index = find_product_index(storage, product_id) + if index is None: + print(f"no product with id {product_id}") + return None + return storage[index] def update_product( @@ -110,8 +138,27 @@ def update_product( 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) + + name, price, quantity = fields + norm_name = normalize_product_name(name) + + if not norm_name: + print("product name must not be blank") + return None + + index = find_product_index(storage, product_id) + if index is None: + print(f"no product with id {product_id}") + return None + + for product in storage: + if product[PRODUCT_ID_INDEX] != product_id and product[NAME_INDEX] == norm_name: + print(f"product name '{norm_name}' is already taken") + return None + + updated_product = (product_id, norm_name, normalize_price(price), quantity) + storage[index] = updated_product + return updated_product def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -127,5 +174,11 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: product carried that identifier (``storage`` is left unchanged and a message is printed). """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return 0 + + index = find_product_index(storage, product_id) + if index is None: + print(f"no product with id {product_id}") + return None + + storage.pop(index) + return product_id diff --git a/src/part3/run_admin.py b/src/part3/run_admin.py index c5feeb0b..3671c2b6 100644 --- a/src/part3/run_admin.py +++ b/src/part3/run_admin.py @@ -29,22 +29,32 @@ 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 # noqa: F401 +from .utils import get_storage_str_representation -# 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: @@ -54,7 +64,7 @@ def show_help() -> None: is: a heading, one line per command with a short description, and a note on how multi-word names are parsed. """ - # TODO: реализуйте функцию + print(HELP_TEXT) def print_result(result: object) -> None: @@ -65,7 +75,8 @@ def print_result(result: object) -> None: 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: @@ -88,8 +99,46 @@ def run_command(storage: list[Product], line: str) -> bool: 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 ["exit"]: + return False + + case ["help"]: + show_help() + return True + + case ["show"]: + print(get_storage_str_representation(storage)) + return True + + case ["create", *name, price, quantity] if name: + print_result( + create_product(storage, (" ".join(name), Decimal(price), int(quantity))) + ) + return True + + case ["read", product_id]: + print_result(read_product(storage, int(product_id))) + return True + + case ["update", product_id, *name, price, quantity] if name: + print_result( + update_product( + storage, + int(product_id), + (" ".join(name), Decimal(price), int(quantity)), + ) + ) + return True + + case ["delete", product_id]: + print_result(delete_product(storage, int(product_id))) + return True + + case _: + print(f"'{line}' is not a command") + return True def main() -> None: diff --git a/src/part3/storage.py b/src/part3/storage.py index c5e34be5..facf1a9c 100644 --- a/src/part3/storage.py +++ b/src/part3/storage.py @@ -24,12 +24,10 @@ 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 diff --git a/src/part3/utils.py b/src/part3/utils.py index 318ded0b..0327cade 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -18,24 +18,28 @@ 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 ( + NAME_INDEX, + PRICE_INDEX, + PRODUCT_ID_INDEX, + QUANTITY_INDEX, + Product, +) # 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: @@ -48,8 +52,7 @@ def normalize_price(price: Decimal) -> Decimal: ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, with halves rounded up. """ - # TODO: реализуйте функцию (используйте своё решение части 2) - return Decimal(0) + return price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) def normalize_product_name(name: str) -> str: @@ -66,11 +69,13 @@ def normalize_product_name(name: str) -> str: The result is an empty string when ``name`` holds nothing but whitespace. """ - # TODO: реализуйте функцию - return "" + words = name.split() + return " ".join(words).lower() -# TODO: при необходимости добавьте свои вспомогательные функции +def format_row(values: tuple[str, ...], widths: list[int]) -> str: + cells = [f" {value.ljust(width)} " for value, width in zip(values, widths)] + return "|" + "|".join(cells) + "|" def get_storage_str_representation(storage: list[Product]) -> str: @@ -91,5 +96,29 @@ def get_storage_str_representation(storage: list[Product]) -> str: is empty only the header and separator rows are returned, sized to the header labels. """ - # TODO: реализуйте функцию - return "" + + rows = [TABLE_HEADERS] + for product in storage: + rows.append( + ( + str(product[PRODUCT_ID_INDEX]), + product[NAME_INDEX], + str(product[PRICE_INDEX]), + str(product[QUANTITY_INDEX]), + ) + ) + + col_widths = [] + for col_ind in range(len(TABLE_HEADERS)): + max_width = max(len(row[col_ind]) for row in rows) + col_widths.append(max_width) + + result_lines = [ + format_row(TABLE_HEADERS, col_widths), + "|" + "|".join("-" * (width + 2) for width in col_widths) + "|", + ] + + for row in rows[1:]: + result_lines.append(format_row(row, col_widths)) + + return "\n".join(result_lines) From 236c79c073d4daa799404d32001da7602ffc07a2 Mon Sep 17 00:00:00 2001 From: Lenovo Date: Sun, 1 Nov 2026 19:09:09 +0300 Subject: [PATCH 4/4] Solve task 4 --- src/part4/cart.py | 51 ++++++++++++++++++++---- src/part4/crud.py | 79 ++++++++++++++++++++++++++++++------- src/part4/run_admin.py | 88 ++++++++++++++++++++++++++++++++++++------ src/part4/storage.py | 9 ++--- src/part4/utils.py | 54 +++++++++++++++++++------- 5 files changed, 228 insertions(+), 53 deletions(-) diff --git a/src/part4/cart.py b/src/part4/cart.py index aed9bb72..d10b485d 100644 --- a/src/part4/cart.py +++ b/src/part4/cart.py @@ -9,10 +9,8 @@ an explanatory message to stdout and returns ``None``. """ -from .storage import Product - - -# TODO: при необходимости добавьте свои вспомогательные функции +from .crud import read_product +from .storage import QUANTITY_KEY, Product def add_to_cart( @@ -46,8 +44,23 @@ def add_to_cart( ``None`` when the product is unknown or the store cannot cover the request. """ - # TODO: реализуйте функцию - return 0 + + product = read_product(storage, product_id) + if product is None: + return None + + if product[QUANTITY_KEY] < quantity: + print( + f"not enough stock for product {product_id}: " + f"{product[QUANTITY_KEY]} available, {quantity} requested" + ) + return None + + product[QUANTITY_KEY] -= quantity + new_cart_quantity = cart.get(product_id, 0) + quantity + if new_cart_quantity > 0: + cart[product_id] = new_cart_quantity + return new_cart_quantity def remove_from_cart( @@ -83,5 +96,27 @@ def remove_from_cart( (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 + + in_cart = cart.get(product_id) + if in_cart is None: + print(f"product {product_id} is not in the cart") + return None + + if in_cart < quantity: + print( + f"cart holds only {in_cart} unit(s) of product " + f"{product_id}, cannot remove {quantity}" + ) + return None + + product = read_product(storage, product_id) + if product is None: + return None + + product[QUANTITY_KEY] += quantity + new_cart_quantity = in_cart - quantity + if new_cart_quantity == 0: + del cart[product_id] + else: + cart[product_id] = new_cart_quantity + return new_cart_quantity diff --git a/src/part4/crud.py b/src/part4/crud.py index 471eff00..8de2f25a 100644 --- a/src/part4/crud.py +++ b/src/part4/crud.py @@ -23,16 +23,16 @@ 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: @@ -41,8 +41,8 @@ def generate_product_id() -> str: Returns: A freshly generated UUID, stringified. """ - # TODO: реализуйте функцию - return "" + + return str(uuid.uuid4()) def create_product( @@ -73,8 +73,25 @@ def create_product( and ``product_names`` are left unchanged and an explanatory message is printed. """ - # TODO: реализуйте функцию - return "" + + norm_name = normalize_product_name(fields[NAME_KEY]) + + if not norm_name: + print("product name must not be blank") + return None + + if norm_name in product_names: + print(f"product name '{norm_name}' is already taken") + return None + + product_id = generate_product_id() + storage[product_id] = { + NAME_KEY: norm_name, + PRICE_KEY: normalize_price(fields[PRICE_KEY]), + QUANTITY_KEY: fields[QUANTITY_KEY], + } + product_names.add(norm_name) + return product_id def read_product(storage: dict[str, Product], product_id: str) -> Product | None: @@ -88,8 +105,12 @@ def read_product(storage: dict[str, Product], product_id: str) -> Product | None The matching product record, or ``None`` when no product carries that identifier (a message is printed in that case). """ - # TODO: реализуйте функцию - return {} + + product = storage.get(product_id) + if product is None: + print(f"no product with id {product_id}") + return None + return product def update_product( @@ -129,8 +150,34 @@ def update_product( and an explanatory message is printed. Renaming a product to its own current name is allowed. """ - # TODO: реализуйте функцию - return {} + + product = read_product(storage, product_id) + if product is None: + return None + + old_name = product[NAME_KEY] + + if NAME_KEY in fields: + norm_name = normalize_product_name(fields[NAME_KEY]) + if not norm_name: + print("product name must not be blank") + return None + if norm_name != old_name and norm_name in product_names: + print(f"product name '{norm_name}' is already taken") + return None + fields[NAME_KEY] = norm_name + + if PRICE_KEY in fields: + fields[PRICE_KEY] = normalize_price(fields[PRICE_KEY]) + + product.update(fields) + + new_name = product[NAME_KEY] + if new_name != old_name: + product_names.discard(old_name) + product_names.add(new_name) + + return product def delete_product( @@ -153,5 +200,11 @@ def delete_product( product carried that identifier (``storage`` and ``product_names`` are left unchanged and a message is printed). """ - # TODO: реализуйте функцию - return "" + + product = read_product(storage, product_id) + if product is None: + return None + + product_names.discard(product[NAME_KEY]) + del storage[product_id] + return product_id diff --git a/src/part4/run_admin.py b/src/part4/run_admin.py index 2247b29b..80c62101 100644 --- a/src/part4/run_admin.py +++ b/src/part4/run_admin.py @@ -28,22 +28,32 @@ is left untouched and the loop keeps running; only ``exit`` stops it. """ -from decimal import Decimal, InvalidOperation # noqa: F401 -from typing import Final +from decimal import Decimal, InvalidOperation +from typing import Any, 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: @@ -53,7 +63,8 @@ def show_help() -> None: 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) + + print(HELP_TEXT) def print_result(result: object) -> None: @@ -64,7 +75,17 @@ def print_result(result: object) -> None: 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 build_fields(name: str, price: str, quantity: str) -> dict[str, Any]: + return { + NAME_KEY: name, + PRICE_KEY: Decimal(price), + QUANTITY_KEY: int(quantity), + } def run_command( @@ -91,8 +112,51 @@ def run_command( 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 ["exit"]: + return False + + case ["help"]: + show_help() + return True + + case ["show"]: + print(get_storage_str_representation(storage)) + return True + + case ["create", *name, price, quantity] if name: + print_result( + create_product( + storage, + product_names, + build_fields(" ".join(name), price, quantity), + ) + ) + return True + + case ["read", product_id]: + print_result(read_product(storage, product_id)) + return True + + case ["update", product_id, *name, price, quantity] if name: + print_result( + update_product( + storage, + product_names, + product_id, + build_fields(" ".join(name), price, quantity), + ) + ) + return True + + case ["delete", product_id]: + print_result(delete_product(storage, product_names, product_id)) + return True + + case _: + print(f"'{line}' is not a command") + return True def main() -> None: diff --git a/src/part4/storage.py b/src/part4/storage.py index 9acedf07..5375750b 100644 --- a/src/part4/storage.py +++ b/src/part4/storage.py @@ -38,8 +38,7 @@ type Product = dict[str, Any] -# 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" diff --git a/src/part4/utils.py b/src/part4/utils.py index d2a940ea..43ae79ad 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, @@ -31,16 +31,13 @@ # 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) +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, ...]] = () +TABLE_HEADERS: Final[tuple[str, ...]] = ("ID", "name", "price", "quantity") def normalize_price(price: Decimal) -> Decimal: @@ -53,8 +50,8 @@ def normalize_price(price: Decimal) -> Decimal: ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, with halves rounded up. """ - # TODO: реализуйте функцию (используйте своё решение части 3) - return Decimal(0) + + return price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) def normalize_product_name(name: str) -> str: @@ -71,11 +68,14 @@ def normalize_product_name(name: str) -> str: The result is an empty string when ``name`` holds nothing but whitespace. """ - # TODO: реализуйте функцию (используйте своё решение части 3) - return "" + + words = name.split() + return " ".join(words).lower() -# TODO: при необходимости добавьте свои вспомогательные функции +def format_row(values: tuple[str, ...], widths: list[int]) -> str: + cells = [f" {value.ljust(width)} " for value, width in zip(values, widths)] + return "|" + "|".join(cells) + "|" def get_storage_str_representation(storage: dict[str, Product]) -> str: @@ -96,5 +96,29 @@ def get_storage_str_representation(storage: dict[str, Product]) -> str: ``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 "" + + rows = [TABLE_HEADERS] + for product_id, product in storage.items(): + rows.append( + ( + product_id, + product[NAME_KEY], + str(product[PRICE_KEY]), + str(product[QUANTITY_KEY]), + ) + ) + + col_widths = [] + for col_ind in range(len(TABLE_HEADERS)): + max_width = max(len(row[col_ind]) for row in rows) + col_widths.append(max_width) + + result_lines = [ + format_row(TABLE_HEADERS, col_widths), + "|" + "|".join("-" * (width + 2) for width in col_widths) + "|", + ] + + for row in rows[1:]: + result_lines.append(format_row(row, col_widths)) + + return "\n".join(result_lines)