diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..7a112a77 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..e2f234e7 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -13,12 +13,13 @@ :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, ) @@ -34,8 +35,7 @@ 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() * 1000.0 - epoch_ms) def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: @@ -50,8 +50,7 @@ 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 >> (NODE_ID_MAX + SEQUENCE_ID_MAX)) + epoch_ms def decode_node_id(snowflake_id: int) -> int: @@ -64,8 +63,7 @@ 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 +76,7 @@ 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 +107,21 @@ 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}], but is {node_id}") + return None + + if not (0 <= sequence_id <= SEQUENCE_ID_MAX): + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], but is {sequence_id}") + return None + + timestamp = read_current_millis(epoch_ms) + if timestamp > TIMESTAMP_MS_MAX: + print("timestamp overflows") + return None + + return ( + (timestamp << (NODE_ID_MAX + SEQUENCE_ID_MAX)) + | (node_id << SEQUENCE_ID_BITS) + | sequence_id + ) diff --git a/src/part2/cart.py b/src/part2/cart.py index 063f9aea..37114ed8 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 +22,19 @@ 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_line( + cart: list[CartLine], + product_id: int, +) -> CartLine | None: + for cart_line in cart: + if cart_line[LINE_PRODUCT_ID_INDEX] == product_id: + return cart_line + return None def add_to_cart( @@ -53,8 +63,46 @@ 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_in_storage = read_product(storage, product_id) + if product_in_storage is None: + return None + + available_quantity = product_in_storage[QUANTITY_INDEX] + if available_quantity < quantity: + print( + f"not enough stock for product {product_id}: " + f"{available_quantity} available, {quantity} requested" + ) + return None + + update_product( + storage, + product_id, + ( + product_in_storage[NAME_INDEX], + product_in_storage[PRICE_INDEX], + available_quantity - quantity, + ), + ) + + final_cartline: CartLine + product_already_in_cart = False + + for cartline_index in range(len(cart)): + if product_id == cart[cartline_index][LINE_PRODUCT_ID_INDEX]: + final_cartline = ( + product_id, + cart[cartline_index][LINE_QUANTITY_INDEX] + quantity, + ) + cart[cartline_index] = final_cartline + product_already_in_cart = True + break + + if not product_already_in_cart: + final_cartline = (product_id, quantity) + cart.append(final_cartline) + + return final_cartline def remove_from_cart( @@ -85,5 +133,37 @@ 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) + 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 + + quantity_in_cart = cart_line[LINE_QUANTITY_INDEX] + if quantity_in_cart < quantity: + print( + f"cart holds only {quantity_in_cart} unit(s) " + f"of product {product_id}, cannot remove {quantity}" + ) + return None + + product = read_product(storage, product_id) + if product is None: + return None + + quantity_in_product = product[QUANTITY_INDEX] + update_product( + storage, + product_id, + (product[NAME_INDEX], product[PRICE_INDEX], quantity_in_product + quantity), + ) + + new_cart_line: CartLine = (product_id, quantity_in_cart - quantity) + cart_line_index = cart.index(cart_line) + + if (quantity_in_cart - quantity) != 0: + cart[cart_line_index] = new_cart_line + else: + cart.pop(cart_line_index) + + return new_cart_line diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..69db93a7 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 +34,13 @@ 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 len(storage) == 0: + return PRODUCT_ID_MIN + + max_id: int = 0 + for product in storage: + max_id = max(product[PRODUCT_ID_INDEX], max_id) + return max_id + 1 def create_product( @@ -56,8 +61,18 @@ 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 name == product[NAME_INDEX]: + print(f"product name '{name}' is already taken") + return None + + new_id = generate_product_id(storage) + new_price = normalize_price(price) + new_product_tuple = (new_id, name, new_price, quantity) + storage.append(new_product_tuple) + return new_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -72,8 +87,12 @@ 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) + for product in storage: + if product_id == product[PRODUCT_ID_INDEX]: + return product + + print(f"no product with id {product_id}") + return None def update_product( @@ -99,8 +118,17 @@ 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 + new_price = normalize_price(price) + new_product: Product = (product_id, name, new_price, quantity) + + for product_index in range(len(storage)): + if product_id == storage[product_index][PRODUCT_ID_INDEX]: + storage[product_index] = 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: @@ -116,5 +144,10 @@ 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_index in range(len(storage)): + if product_id == storage[product_index][PRODUCT_ID_INDEX]: + storage.pop(product_index) + 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 11bd7a76..ba133eb1 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 +24,4 @@ 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, ROUND_HALF_UP) diff --git a/src/part3/crud.py b/src/part3/crud.py index 68811d7e..476be7d3 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: @@ -40,8 +40,13 @@ 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 len(storage) == 0: + return PRODUCT_ID_MIN + + max_id: int = 0 + for product in storage: + max_id = max(product[PRODUCT_ID_INDEX], max_id) + return max_id + 1 def create_product( @@ -64,8 +69,24 @@ 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 + + name = normalize_product_name(name) + + if not name: + print("product name must not be blank") + return None + + for product in storage: + if name == product[NAME_INDEX]: + print(f"product name '{name}' is already taken") + return None + + new_id = generate_product_id(storage) + new_price = normalize_price(price) + new_product_tuple = (new_id, name, new_price, quantity) + storage.append(new_product_tuple) + return new_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -80,8 +101,12 @@ 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 (используйте своё решение части 2) - return (0, "", Decimal(0), 0) + for product in storage: + if product_id == product[PRODUCT_ID_INDEX]: + return product + + print(f"no product with id {product_id}") + return None def update_product( @@ -110,8 +135,29 @@ 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 + + name = normalize_product_name(name) + + if not name: + print("product name must not be blank") + return None + + new_price = normalize_price(price) + new_product: Product = (product_id, name, new_price, quantity) + + for product in storage: + if product_id != product[PRODUCT_ID_INDEX] and product[NAME_INDEX] == name: + print(f"product name '{name}' is already taken") + return None + + for product_index in range(len(storage)): + if product_id == storage[product_index][PRODUCT_ID_INDEX]: + storage[product_index] = 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: @@ -127,5 +173,10 @@ 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 (используйте своё решение части 2) - return 0 + for product_index in range(len(storage)): + if product_id == storage[product_index][PRODUCT_ID_INDEX]: + storage.pop(product_index) + return product_id + + 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 c5feeb0b..cecba5e9 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 +99,45 @@ 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 ["help"]: + show_help() + return True + + case ["exit"]: + return False + + 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 the command") + return True def main() -> None: diff --git a/src/part3/storage.py b/src/part3/storage.py index c5e34be5..c516645b 100644 --- a/src/part3/storage.py +++ b/src/part3/storage.py @@ -24,12 +24,9 @@ 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..8875e564 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -18,24 +18,22 @@ 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 +46,7 @@ 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, ROUND_HALF_UP) def normalize_product_name(name: str) -> str: @@ -66,11 +63,7 @@ def normalize_product_name(name: str) -> str: The result is an empty string when ``name`` holds nothing but whitespace. """ - # TODO: реализуйте функцию - return "" - - -# TODO: при необходимости добавьте свои вспомогательные функции + return " ".join(name.lower().split()) def get_storage_str_representation(storage: list[Product]) -> str: @@ -91,5 +84,36 @@ 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 = [] + 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 i, header in enumerate(TABLE_HEADERS): + max_len = len(header) + for row in rows: + max_len = max(max_len, len(row[i])) + col_widths.append(max_len) + + header_cells = [ + f" {header.ljust(col_widths[i])} " for i, header in enumerate(TABLE_HEADERS) + ] + header_row = f"|{'|'.join(header_cells)}|" + + sep_cells = ["-" * (width + 2) for width in col_widths] + sep_row = f"|{'|'.join(sep_cells)}|" + + result_rows = [header_row, sep_row] + + for row in rows: + data_cells = [f" {cell.ljust(col_widths[i])} " for i, cell in enumerate(row)] + result_rows.append(f"|{'|'.join(data_cells)}|") + + return "\n".join(result_rows) diff --git a/src/part4/cart.py b/src/part4/cart.py index aed9bb72..062bb085 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 +44,22 @@ 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 + + cart[product_id] = cart.get(product_id, 0) + quantity + + return cart[product_id] def remove_from_cart( @@ -83,5 +95,28 @@ 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 + quantity_in_cart = cart.get(product_id) + if quantity_in_cart is None: + print(f"product {product_id} is not in the cart") + return None + + if quantity_in_cart < quantity: + print( + f"cart holds only {quantity_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 + quantity_in_cart -= quantity + + if quantity_in_cart == 0: + del cart[product_id] + else: + cart[product_id] = quantity_in_cart + + return quantity_in_cart diff --git a/src/part4/crud.py b/src/part4/crud.py index 471eff00..67616fe9 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 +41,7 @@ def generate_product_id() -> str: Returns: A freshly generated UUID, stringified. """ - # TODO: реализуйте функцию - return "" + return str(uuid.uuid4) def create_product( @@ -73,8 +72,27 @@ def create_product( and ``product_names`` are left unchanged and an explanatory message is printed. """ - # TODO: реализуйте функцию - return "" + name = normalize_product_name(fields[NAME_KEY]) + + if not name: + print("product name must not be blank") + return None + + if name in product_names: + print(f"product name '{name}' is already taken") + return None + + new_id = generate_product_id() + + storage[new_id] = { + NAME_KEY: name, + PRICE_KEY: normalize_price(fields[PRICE_KEY]), + QUANTITY_KEY: fields[QUANTITY_KEY], + } + + product_names.add(name) + + return new_id def read_product(storage: dict[str, Product], product_id: str) -> Product | None: @@ -88,8 +106,13 @@ 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 +152,35 @@ 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]) + fields[NAME_KEY] = norm_name + + 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 + + if PRICE_KEY in fields: + norm_price = normalize_price(fields[PRICE_KEY]) + fields[PRICE_KEY] = norm_price + + product.update(fields) + + if product[NAME_KEY] != old_name: + product_names.discard(old_name) + product_names.add(product[NAME_KEY]) + + return product def delete_product( @@ -153,5 +203,12 @@ 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 + + del storage[product_id] + + product_names.discard(product[NAME_KEY]) + + return product_id diff --git a/src/part4/run_admin.py b/src/part4/run_admin.py index 2247b29b..cd0e5c00 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 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: @@ -53,7 +63,7 @@ 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 (используйте своё решение части 3) + print(HELP_TEXT) def print_result(result: object) -> None: @@ -64,7 +74,8 @@ 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 run_command( @@ -91,8 +102,58 @@ 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 ["help"]: + show_help() + return True + + case ["exit"]: + return False + + case ["show"]: + print(get_storage_str_representation(storage)) + return True + + case ["create", *name, price, quantity] if name: + print_result( + create_product( + storage, + product_names, + { + NAME_KEY: " ".join(name), + PRICE_KEY: Decimal(price), + QUANTITY_KEY: int(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, + { + NAME_KEY: " ".join(name), + PRICE_KEY: Decimal(price), + QUANTITY_KEY: int(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..91c21e4a 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, @@ -29,18 +29,10 @@ ) -# 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 +45,7 @@ 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 3) - return Decimal(0) + return price.quantize(PRICE_STEP, ROUND_HALF_UP) def normalize_product_name(name: str) -> str: @@ -71,11 +62,7 @@ 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 "" - - -# TODO: при необходимости добавьте свои вспомогательные функции + return " ".join(name.lower().split()) def get_storage_str_representation(storage: dict[str, Product]) -> str: @@ -96,5 +83,38 @@ 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 = [] + + 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 i, header in enumerate(TABLE_HEADERS): + max_len = len(header) + for row in rows: + max_len = max(max_len, len(row[i])) + col_widths.append(max_len) + + header_cells = [ + f" {header.ljust(col_widths[i])} " for i, header in enumerate(TABLE_HEADERS) + ] + header_row = f"|{'|'.join(header_cells)}|" + + sep_cells = ["-" * (width + 2) for width in col_widths] + sep_row = f"|{'|'.join(sep_cells)}|" + + result_rows = [header_row, sep_row] + + for row in rows: + data_cells = [f" {cell.ljust(col_widths[i])} " for i, cell in enumerate(row)] + result_rows.append(f"|{'|'.join(data_cells)}|") + + return "\n".join(result_rows)