diff --git a/pl-001-python-basics-task b/pl-001-python-basics-task new file mode 160000 index 00000000..339b23f1 --- /dev/null +++ b/pl-001-python-basics-task @@ -0,0 +1 @@ +Subproject commit 339b23f1a96d511fc3bd06b3871bbfdbb6143c73 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..7dca1200 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 +38,7 @@ 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 +54,7 @@ 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 +68,7 @@ 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 +82,7 @@ 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 +114,19 @@ 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}], have {node_id}") + return None + + if not (0 <= sequence_id <= SEQUENCE_ID_MAX): + print(f"sequence_id must be in [0; {SEQUENCE_ID_MAX}], have {sequence_id}") + return None + + vremya = read_current_millis(epoch_ms) + if vremya > TIMESTAMP_MS_MAX: + print("Timestamps overflows") + return None + + return (vremya << (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..4d5df33d 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 +24,33 @@ # 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 line in cart: + if line[LINE_PRODUCT_ID_INDEX] == product_id: + return line + return None + + +def change_cart_quantity( + cart: list[CartLine], product_id: int, delta: int +) -> CartLine | None: + + for i, line in enumerate(cart): + if line[LINE_PRODUCT_ID_INDEX] == product_id: + new_quantity = line[LINE_QUANTITY_INDEX] + delta + + if new_quantity == 0: + del cart[i] + return None + else: + new_line = (product_id, new_quantity) + cart[i] = new_line + return new_line + return None def add_to_cart( @@ -54,7 +80,29 @@ def add_to_cart( 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 + + new_stock_quantity = stock_quantity - quantity + fields = (product[NAME_INDEX], product[PRICE_INDEX], new_stock_quantity) + update_product(storage, product_id, fields) + + existing_line = find_cart_line(cart, product_id) + if existing_line: + return change_cart_quantity(cart, product_id, quantity) + else: + new_line = (product_id, quantity) + cart.append(new_line) + return new_line def remove_from_cart( @@ -86,4 +134,29 @@ def remove_from_cart( 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 + + cart_quantity = cart_line[LINE_QUANTITY_INDEX] + if cart_quantity < quantity: + print( + f"cart holds only {cart_quantity} unit(s) of product " + f"{product_id}, cannot remove {quantity}" + ) + return None + + product = read_product(storage, product_id) + if product is None: + return None + + new_stock_quantity = product[QUANTITY_INDEX] + quantity + fields = (product[NAME_INDEX], product[PRICE_INDEX], new_stock_quantity) + update_product(storage, product_id, fields) + + result = change_cart_quantity(cart, product_id, -quantity) + + if result is None: + return (product_id, 0) + return result diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..ee9ea22a 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: @@ -35,7 +35,9 @@ def generate_product_id(storage: list[Product]) -> int: 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( @@ -57,7 +59,19 @@ def create_product( 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 + + product_id = generate_product_id(storage) + normalized_price = normalize_price(price) + + new_product = (product_id, name, normalized_price, quantity) + storage.append(new_product) + return product_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -73,7 +87,12 @@ def read_product(storage: list[Product], product_id: int) -> Product | None: 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( @@ -100,7 +119,17 @@ def update_product( left unchanged and a message is printed). """ # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + name, price, quantity = fields + normalized_price = normalize_price(price) + + for i, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + 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: @@ -117,4 +146,10 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: a message is printed). """ # TODO: реализуйте функцию - return 0 + for i, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + del storage[i] + 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..2b6aa266 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 price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) diff --git a/src/part3/crud.py b/src/part3/crud.py index 68811d7e..01eef2e4 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: @@ -41,7 +41,9 @@ def generate_product_id(storage: list[Product]) -> int: 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( @@ -65,7 +67,20 @@ def create_product( 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 product[NAME_INDEX] == name: + print(f"product name '{name}' is already taken") + return None + product_id = generate_product_id(storage) + price = normalize_price(price) + new_product = (product_id, name, price, quantity) + storage.append(new_product) + return product_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -81,7 +96,11 @@ def read_product(storage: list[Product], product_id: int) -> Product | None: printed in that case). """ # TODO: реализуйте функцию (используйте своё решение части 2) - 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( @@ -111,7 +130,27 @@ def update_product( 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 + target_index = None + for i, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + target_index = i + break + if target_index is None: + print(f"no product with id {product_id}") + return None + for product in storage: + if product[NAME_INDEX] == name and product[PRODUCT_ID_INDEX] != product_id: + print(f"product name '{name}' is already taken") + return None + price = normalize_price(price) + updated_product = (product_id, name, price, quantity) + storage[target_index] = updated_product + return updated_product def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -128,4 +167,9 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: a message is printed). """ # TODO: реализуйте функцию (используйте своё решение части 2) - return 0 + for i, product in enumerate(storage): + if product[PRODUCT_ID_INDEX] == product_id: + del storage[i] + 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..d4ee4b70 100644 --- a/src/part3/run_admin.py +++ b/src/part3/run_admin.py @@ -29,7 +29,7 @@ it. """ -from decimal import Decimal, InvalidOperation # noqa: F401 +from decimal import Decimal, InvalidOperation from typing import Final from .crud import ( # noqa: F401 @@ -39,12 +39,23 @@ 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: @@ -55,6 +66,7 @@ def show_help() -> None: note on how multi-word names are parsed. """ # TODO: реализуйте функцию + print(HELP_TEXT) def print_result(result: object) -> None: @@ -66,6 +78,8 @@ def print_result(result: object) -> None: printed in that case. """ # TODO: реализуйте функцию + if result is not None: + print(result) def run_command(storage: list[Product], line: str) -> bool: @@ -89,13 +103,51 @@ def run_command(storage: list[Product], line: str) -> bool: ``update`` does not parse as a decimal number. """ # TODO: реализуйте функцию - return False + parts = line.split() + if not parts: + return True + command = parts[0] + if command == "help": + show_help() + elif command == "exit": + return False + elif command == "show": + print(get_storage_str_representation(storage)) + elif command == "read" or command == "delete": + if len(parts) != 2: + print(f"'{line}' is not a command") + return True + product_id = int(parts[1]) + print_result(read_product(storage, product_id)) + elif command == "create": + if len(parts) < 4: + print(f"'{line}' is not a command") + return True + name = " ".join(parts[1:-2]) + price = Decimal(parts[-2]) + quantity = int(parts[-1]) + result = create_product(storage, (name, price, quantity)) + print_result(result) + elif command == "update": + if len(parts) < 5: + print(f"'{line}' is not a command") + return True + product_id = int(parts[1]) + name = " ".join(parts[2:-2]) + price = Decimal(parts[-2]) + quantity = int(parts[-1]) + updated = update_product(storage, product_id, (name, price, quantity)) + print_result(updated) + else: + print(f"'{line}' is not a command") + + return True def main() -> None: """Run the admin console until the ``exit`` command is entered. - A single product store is created empty and kept in memory for the + A sngle product store is created empty and kept in memory for the whole session. Each iteration reads one line from stdin, strips its surrounding whitespace and hands it to :func:`run_command`. A line that names a command but whose id, price or quantity argument does diff --git a/src/part3/storage.py b/src/part3/storage.py index c5e34be5..36e9af7f 100644 --- a/src/part3/storage.py +++ b/src/part3/storage.py @@ -27,9 +27,9 @@ # 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..136bfc33 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -18,24 +18,30 @@ 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("0.01") # 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", "quatity") def normalize_price(price: Decimal) -> Decimal: @@ -49,7 +55,7 @@ def normalize_price(price: Decimal) -> Decimal: 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: @@ -67,7 +73,7 @@ def normalize_product_name(name: str) -> str: whitespace. """ # TODO: реализуйте функцию - return "" + return " ".join(name.split()).lower() # TODO: при необходимости добавьте свои вспомогательные функции @@ -92,4 +98,27 @@ def get_storage_str_representation(storage: list[Product]) -> str: the header labels. """ # TODO: реализуйте функцию - return "" + rows_data = [] + for product in storage: + rows_data.append( + ( + str(product[PRODUCT_ID_INDEX]), + str(product[NAME_INDEX]), + str(product[PRICE_INDEX]), + str(product[QUANTITY_INDEX]), + ) + ) + widths = [len(header) for header in TABLE_HEADERS] + for row in rows_data: + for i, cell in enumerate(row): + widths[i] = max(widths[i], len(cell)) + header_cells = [f"{header:<{widths[i]}}" for i, header in enumerate(TABLE_HEADERS)] + header_line = "| " + " | ".join(header_cells) + " |" + separator_cells = ["-" * (widths[i] + 2) for i in range(len(TABLE_HEADERS))] + separator_line = "|" + "|".join(separator_cells) + "|" + data_lines = [] + for row in rows_data: + cells = [f"{cell:<{widths[i]}}" for i, cell in enumerate(row)] + data_lines.append("| " + " | ".join(cells) + " |") + result_lines = [header_line, separator_line] + data_lines + return "\n".join(result_lines) diff --git a/src/part4/cart.py b/src/part4/cart.py index aed9bb72..8b7b5e79 100644 --- a/src/part4/cart.py +++ b/src/part4/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 @@ -47,7 +47,19 @@ def add_to_cart( request. """ # TODO: реализуйте функцию - return 0 + if product_id not in storage: + print(f"no product with id {product_id}") + return None + available = storage[product_id][QUANTITY_KEY] + if available < quantity: + print( + f"not enough stock for product {product_id}: " + f"{available} available, {quantity} requested" + ) + return None + storage[product_id][QUANTITY_KEY] -= quantity + cart[product_id] = cart.get(product_id, 0) + quantity + return cart[product_id] def remove_from_cart( @@ -84,4 +96,26 @@ def remove_from_cart( the cart does not hold the product or holds too few units. """ # TODO: реализуйте функцию - return 0 + if product_id not in cart: + print(f"product {product_id} is not in the cart") + return None + + in_cart = cart[product_id] + if in_cart < quantity: + print( + f"cart holds only {in_cart} unit(s) of product {product_id}, " + f"cannot remove {quantity}" + ) + return None + + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + storage[product_id][QUANTITY_KEY] += quantity + cart[product_id] -= quantity + + if cart[product_id] == 0: + del cart[product_id] + return 0 + return cart[product_id] diff --git a/src/part4/crud.py b/src/part4/crud.py index 471eff00..c0caed9f 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: @@ -42,7 +42,7 @@ def generate_product_id() -> str: A freshly generated UUID, stringified. """ # TODO: реализуйте функцию - return "" + return str(uuid.uuid4()) def create_product( @@ -74,7 +74,21 @@ def create_product( message is printed. """ # TODO: реализуйте функцию - return "" + name = normalize_product_name(str(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 + product_id = generate_product_id() + storage[product_id] = { + NAME_KEY: name, + PRICE_KEY: normalize_price(fields[PRICE_KEY]), + QUANTITY_KEY: fields[QUANTITY_KEY], + } + product_names.add(name) + return product_id def read_product(storage: dict[str, Product], product_id: str) -> Product | None: @@ -89,7 +103,10 @@ def read_product(storage: dict[str, Product], product_id: str) -> Product | None that identifier (a message is printed in that case). """ # TODO: реализуйте функцию - return {} + if product_id not in storage: + print(f"no product with id {product_id}") + return None + return storage[product_id] def update_product( @@ -130,7 +147,30 @@ def update_product( 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 + + old_name = storage[product_id][NAME_KEY] + + if NAME_KEY in fields: + new_name = normalize_product_name(str(fields[NAME_KEY])) + if not new_name: + print("product name must not be blank") + return None + if new_name != old_name and new_name in product_names: + print(f"product name '{new_name}' is already taken") + return None + product_names.remove(old_name) + product_names.add(new_name) + storage[product_id][NAME_KEY] = new_name + if PRICE_KEY in fields: + storage[product_id][PRICE_KEY] = normalize_price(fields[PRICE_KEY]) + + if QUANTITY_KEY in fields: + storage[product_id][QUANTITY_KEY] = fields[QUANTITY_KEY] + + return storage[product_id] def delete_product( @@ -154,4 +194,11 @@ def delete_product( 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 + + name = storage[product_id][NAME_KEY] + product_names.remove(name) + del storage[product_id] + return product_id diff --git a/src/part4/run_admin.py b/src/part4/run_admin.py index 2247b29b..9e3aed66 100644 --- a/src/part4/run_admin.py +++ b/src/part4/run_admin.py @@ -28,22 +28,33 @@ 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: @@ -54,6 +65,7 @@ def show_help() -> None: 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: @@ -65,6 +77,8 @@ def print_result(result: object) -> None: printed in that case. """ # TODO: реализуйте функцию (используйте своё решение части 3) + if result is not None: + print(result) def run_command( @@ -92,7 +106,56 @@ def run_command( ``update`` does not parse as a decimal number. """ # TODO: реализуйте функцию - return False + parts = line.split() + if not parts: + return True + + command = parts[0] + + match command: + case "help": + show_help() + case "exit": + return False + case "show": + print(get_storage_str_representation(storage)) + case "read": + if len(parts) != 2: + print(f"'{line}' is not a command") + return True + print_result(read_product(storage, parts[1])) + case "delete": + if len(parts) != 2: + print(f"'{line}' is not a command") + return True + print_result(delete_product(storage, product_names, parts[1])) + case "create": + if len(parts) < 4: + print(f"'{line}' is not a command") + return True + name = " ".join(parts[1:-2]) + price = Decimal(parts[-2]) + quantity = int(parts[-1]) + + fields = {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity} + result = create_product(storage, product_names, fields) + print_result(result) + case "update": + if len(parts) < 5: + print(f"'{line}' is not a command") + return True + product_id = parts[1] + name = " ".join(parts[2:-2]) + price = Decimal(parts[-2]) + quantity = int(parts[-1]) + + fields = {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity} + updated = update_product(storage, product_names, product_id, fields) + print_result(updated) + 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..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" diff --git a/src/part4/utils.py b/src/part4/utils.py index d2a940ea..c0a0cbfa 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, @@ -33,14 +33,14 @@ # 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("0.01") # 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: @@ -54,7 +54,7 @@ def normalize_price(price: Decimal) -> Decimal: 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: @@ -72,7 +72,7 @@ def normalize_product_name(name: str) -> str: whitespace. """ # TODO: реализуйте функцию (используйте своё решение части 3) - return "" + return " ".join(name.split()).lower() # TODO: при необходимости добавьте свои вспомогательные функции @@ -97,4 +97,31 @@ def get_storage_str_representation(storage: dict[str, Product]) -> str: returned, sized to the header labels. """ # TODO: реализуйте функцию (используйте своё решение части 3) - return "" + rows_data = [] + for product_id, product in storage.items(): + rows_data.append( + ( + str(product_id), + str(product[NAME_KEY]), + str(product[PRICE_KEY]), + str(product[QUANTITY_KEY]), + ) + ) + widths = [len(header) for header in TABLE_HEADERS] + for row in rows_data: + for i, cell in enumerate(row): + widths[i] = max(widths[i], len(cell)) + + header_cells = [f"{header:<{widths[i]}}" for i, header in enumerate(TABLE_HEADERS)] + header_line = "| " + " | ".join(header_cells) + " |" + + separator_cells = ["-" * (widths[i] + 2) for i in range(len(TABLE_HEADERS))] + separator_line = "|" + "|".join(separator_cells) + "|" + + data_lines = [] + for row in rows_data: + cells = [f"{cell:<{widths[i]}}" for i, cell in enumerate(row)] + data_lines.append("| " + " | ".join(cells) + " |") + + result_lines = [header_line, separator_line] + data_lines + return "\n".join(result_lines)