diff --git a/Install b/Install new file mode 100644 index 00000000..e69de29b diff --git a/Ruff b/Ruff new file mode 100644 index 00000000..e69de29b diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..588fe9f8 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -19,20 +19,20 @@ # 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). diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index d3abf050..c8a703fa 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -13,13 +13,16 @@ :func:`decode_node_id` and :func:`decode_sequence_id`. """ -import time # noqa: F401 +import time from .constants import ( # noqa: F401 EPOCH_MS_DEFAULT, + NODE_ID_BITS, NODE_ID_DEFAULT, NODE_ID_MAX, + SEQUENCE_ID_BITS, SEQUENCE_ID_MAX, + TIMESTAMP_BITS, TIMESTAMP_MS_MAX, ) @@ -35,7 +38,8 @@ def read_current_millis(epoch_ms: int) -> int: 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: @@ -51,7 +55,8 @@ def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> generated. """ # TODO: реализуйте функцию - return 0 + + return epoch_ms + (snowflake_id >> (NODE_ID_BITS + SEQUENCE_ID_BITS)) def decode_node_id(snowflake_id: int) -> int: @@ -65,7 +70,7 @@ def decode_node_id(snowflake_id: int) -> int: ``[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: @@ -79,7 +84,7 @@ def decode_sequence_id(snowflake_id: int) -> int: the range ``[0, SEQUENCE_ID_MAX]``. """ # TODO: реализуйте функцию - return 0 + return snowflake_id & SEQUENCE_ID_MAX def generate_snowflake_id( @@ -111,4 +116,19 @@ def generate_snowflake_id( 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}], you have {node_id}") + return None + if not (0 <= sequence_id <= SEQUENCE_ID_MAX): + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], you have {sequence_id}") + return None + time_ms = read_current_millis(epoch_ms) + if time_ms > TIMESTAMP_MS_MAX: + print("Timestamps overflows") + return None + return ( + (time_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 063f9aea..4c5751b5 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, @@ -24,7 +24,14 @@ # 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_line(cart: list[CartLine], product_id: int) -> int | None: + for i, line in enumerate(cart): + if line[LINE_PRODUCT_ID_INDEX] == product_id: + return i + 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 + + left_product = product[QUANTITY_INDEX] + if left_product < quantity: + print( + f"not enough stock for product {product_id}: {left_product} available, {quantity} requested" + ) + return None + + update_product( + storage, + product_id, + (product[NAME_INDEX], product[PRICE_INDEX], left_product - quantity), + ) + + line_index = find_line(cart, product_id) + if line_index is not None: + new_quantity = cart[line_index][LINE_QUANTITY_INDEX] + quantity + new_line = (product_id, new_quantity) + cart[line_index] = new_line + return new_line + + new_line = (product_id, quantity) + cart.append(new_line) + return new_line def remove_from_cart( @@ -86,4 +118,35 @@ def remove_from_cart( line for the product or holds too few units. """ # TODO: реализуйте функцию - return (0, 0) + + line_index = find_line(cart, product_id) + if line_index is None: + print(f"product {product_id} is not in the cart") + return None + + cart_quantity = cart[line_index][LINE_QUANTITY_INDEX] + if cart_quantity < quantity: + print( + f"cart holds only {cart_quantity} unit(s) of product {product_id}, cannot remove {quantity}" + ) + return None + + product = read_product(storage, product_id) + if product is None: + return None + + left_product = product[QUANTITY_INDEX] + update_product( + storage, + product_id, + (product[NAME_INDEX], product[PRICE_INDEX], left_product + quantity), + ) + + new_quantity = cart[line_index][LINE_QUANTITY_INDEX] - quantity + if new_quantity == 0: + del cart[line_index] + return (product_id, 0) + + new_line = (product_id, new_quantity) + cart[line_index] = new_line + return new_line diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..af9bee16 100644 --- a/src/part2/crud.py +++ b/src/part2/crud.py @@ -14,13 +14,13 @@ 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 # noqa: F401 +from .utils import normalize_price def generate_product_id(storage: list[Product]) -> int: @@ -34,8 +34,9 @@ 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 +57,18 @@ 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 + + id_product = generate_product_id(storage) + normalized_price = normalize_price(price) + + new_product = (id_product, name, normalized_price, quantity) + storage.append(new_product) + return id_product def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -72,8 +83,11 @@ 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 - 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( @@ -99,8 +113,15 @@ 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 + for i, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + normalized_price = normalize_price(price) + updated_product = (product_id, name, normalized_price, quantity) + storage[i] = updated_product + return updated_product + print(f"no product with id {product_id}") + return None def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -116,5 +137,10 @@ 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 + + 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 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 diff --git a/src/part2/utils.py b/src/part2/utils.py index ec0348d3..ab162ad5 100644 --- a/src/part2/utils.py +++ b/src/part2/utils.py @@ -6,13 +6,13 @@ 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: @@ -26,4 +26,4 @@ def normalize_price(price: Decimal) -> Decimal: with halves rounded up. """ # TODO: реализуйте функцию - return Decimal(0) + return Decimal(price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP))