diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..bff179aa 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -19,20 +19,23 @@ # 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] = (1 << TIMESTAMP_BITS) - 1 +NODE_ID_MAX: Final[int] = (1 << NODE_ID_BITS) - 1 +SEQUENCE_ID_MAX: Final[int] = (1 << SEQUENCE_ID_BITS) - 1 # Здесь можно добавить собственные вспомогательные константы # (например, сдвиги полей при сборке идентификатора). +SEQUENCE_ID_SHIFT: Final[int] = 0 # справа(младшие разряды) +NODE_ID_SHIFT: Final[int] = SEQUENCE_ID_BITS +TIMESTAMP_SHIFT: Final[int] = SEQUENCE_ID_BITS + NODE_ID_BITS diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index d3abf050..56204d22 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -13,14 +13,17 @@ :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, + NODE_ID_SHIFT, + SEQUENCE_ID_BITS, SEQUENCE_ID_MAX, TIMESTAMP_MS_MAX, + TIMESTAMP_SHIFT, ) @@ -34,8 +37,7 @@ 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) - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: @@ -51,7 +53,8 @@ def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> generated. """ # TODO: реализуйте функцию - return 0 + time_res = snowflake_id >> TIMESTAMP_SHIFT + return time_res + epoch_ms def decode_node_id(snowflake_id: int) -> int: @@ -65,7 +68,8 @@ def decode_node_id(snowflake_id: int) -> int: ``[0, NODE_ID_MAX]``. """ # TODO: реализуйте функцию - return 0 + node_id = (snowflake_id >> SEQUENCE_ID_BITS) & NODE_ID_MAX + return node_id def decode_sequence_id(snowflake_id: int) -> int: @@ -79,7 +83,8 @@ def decode_sequence_id(snowflake_id: int) -> int: the range ``[0, SEQUENCE_ID_MAX]``. """ # TODO: реализуйте функцию - return 0 + sequence_id = snowflake_id & SEQUENCE_ID_MAX + return sequence_id 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}], but you wrote {node_id}") + return None + if not (0 <= sequence_id <= SEQUENCE_ID_MAX): + print( + f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], but you wrote {sequence_id}" + ) + return None + timestamp = read_current_millis(epoch_ms) + if not (0 <= timestamp <= TIMESTAMP_MS_MAX): + print("overflows") + return None + node_res = node_id << NODE_ID_SHIFT + timestamp_res = timestamp << TIMESTAMP_SHIFT + result = timestamp_res | node_res | sequence_id + return result diff --git a/src/part2/cart.py b/src/part2/cart.py index 063f9aea..51afb1e5 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_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 add_to_cart( @@ -54,7 +61,31 @@ 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: + if product[QUANTITY_INDEX] < quantity: + print( + f"not enough stock for product {product_id}: {product[QUANTITY_INDEX]} available, {quantity} requested" + ) + return None + product = update_product( + storage, + product_id, + ( + product[NAME_INDEX], + product[PRICE_INDEX], + product[QUANTITY_INDEX] - quantity, + ), + ) + for line in cart: + if line[LINE_PRODUCT_ID_INDEX] == product_id: + new_line = (product_id, line[LINE_QUANTITY_INDEX] + quantity) + cart[cart.index(line)] = new_line + return new_line + new_line = (product_id, quantity) + cart.append(new_line) + return new_line + return None def remove_from_cart( @@ -86,4 +117,32 @@ def remove_from_cart( line for the product or holds too few units. """ # TODO: реализуйте функцию - return (0, 0) + line = find_cart_line(cart, product_id) + if line is None: + print(f"product {product_id} is not in the cart") + return None + if line[LINE_QUANTITY_INDEX] < quantity: + print( + f"cart holds only {line[LINE_QUANTITY_INDEX]} unit(s) " + f"of product {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 = line[LINE_QUANTITY_INDEX] - quantity + if new_quantity == 0: + cart.remove(line) + return (product_id, 0) + new_line = (product_id, new_quantity) + cart[cart.index(line)] = new_line + return new_line diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..ee88d7e0 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 +35,12 @@ def generate_product_id(storage: list[Product]) -> int: empty. """ # TODO: реализуйте функцию - return 0 + if not storage: + return PRODUCT_ID_MIN + max_id = 0 + for product in storage: + max_id = max(max_id, product[PRODUCT_ID_INDEX]) + return max_id + 1 def create_product( @@ -57,7 +62,15 @@ 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) + storage.append((product_id, name, normalized_price, quantity)) + return product_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -73,7 +86,11 @@ 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 +117,15 @@ def update_product( left unchanged and a message is printed). """ # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + name, price, quantity = fields + price = normalize_price(price) + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + updated_product = (product_id, name, price, quantity) + storage[storage.index(product)] = 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 +142,9 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: 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 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..cda0d7bc 100644 --- a/src/part3/crud.py +++ b/src/part3/crud.py @@ -19,14 +19,31 @@ """ from decimal import Decimal +from typing import cast -from .storage import ( # noqa: F401 +from .storage import ( NAME_INDEX, + PRICE_INDEX, PRODUCT_ID_INDEX, PRODUCT_ID_MIN, + QUANTITY_INDEX, Product, ) -from .utils import normalize_price, normalize_product_name # noqa: F401 +from .utils import normalize_price, normalize_product_name + + +def make( + product_id: int, + name: str, + price: Decimal, + quantity: int, +) -> Product: + fields: list[int | str | Decimal] = [0] * 4 + fields[PRODUCT_ID_INDEX] = product_id + fields[NAME_INDEX] = name + fields[PRICE_INDEX] = price + fields[QUANTITY_INDEX] = quantity + return cast(Product, tuple(fields)) def generate_product_id(storage: list[Product]) -> int: @@ -40,8 +57,12 @@ 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 + max_id = 0 + for product in storage: + max_id = max(max_id, product[PRODUCT_ID_INDEX]) + return max_id + 1 def create_product( @@ -64,8 +85,19 @@ 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 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 + new_id = generate_product_id(storage) + fixed_price = normalize_price(price) + storage.append(make(new_id, name, fixed_price, quantity)) + return new_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -80,8 +112,11 @@ 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) + 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( @@ -110,8 +145,27 @@ 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 + name = normalize_product_name(name) + if name == "": + print("product name must not be blank") + return None + index = -1 + for i in range(len(storage)): + if storage[i][PRODUCT_ID_INDEX] == product_id: + index = i + break + if index == -1: + 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 + fixed_price = normalize_price(price) + new_record = make(product_id, name, fixed_price, quantity) + storage[index] = new_record + return new_record def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -127,5 +181,9 @@ 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 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/part3/run_admin.py b/src/part3/run_admin.py index c5feeb0b..685ef2b6 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 + parts = line.split() + if not parts: + print(f"'{line}' is not a command") + return True + command = parts[0] + if command == "help" and len(parts) == 1: + show_help() + return True + if command == "exit" and len(parts) == 1: + return False + if command == "show" and len(parts) == 1: + print(get_storage_str_representation(storage)) + return True + if command == "create" and len(parts) >= 4: + name = " ".join(parts[1:-2]) + price = Decimal(parts[-2]) + quantity = int(parts[-1]) + new_id = create_product(storage, (name, price, quantity)) + print_result(new_id) + return True + if command == "read" and len(parts) == 2: + product_id = int(parts[1]) + result = read_product(storage, product_id) + print_result(result) + return True + if command == "update" and len(parts) >= 5: + 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) + return True + if command == "delete" and len(parts) == 2: + product_id = int(parts[1]) + res = delete_product(storage, product_id) + print_result(res) + return True + 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..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..94da952d 100644 --- a/src/part3/utils.py +++ b/src/part3/utils.py @@ -18,7 +18,7 @@ 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 @@ -26,16 +26,10 @@ # 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 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 +42,7 @@ 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 +59,31 @@ def normalize_product_name(name: str) -> str: The result is an empty string when ``name`` holds nothing but whitespace. """ - # TODO: реализуйте функцию - return "" + return " ".join(name.split()).lower() -# TODO: при необходимости добавьте свои вспомогательные функции +def rows_separator(widths: list[int]) -> str: + dash_runs = ["-" * (width + 2) for width in widths] + return "|" + "|".join(dash_runs) + "|" + + +def formatted_row(cells: list[str], widths: list[int]) -> str: + res = [] + for i in range(len(cells)): + res.append(cells[i].ljust(widths[i])) # дополнение спраыва пробелами + return "| " + " | ".join(res) + " |" + + +def column_width(rows: list[list[str]]) -> list[int]: # поиск самой длинной ячейки + widths = [] + column_count = len(rows[0]) + for j in range(column_count): + max_width = 0 + for row in rows: + cell = row[j] + max_width = max(max_width, len(cell)) + widths.append(max_width) + return widths def get_storage_str_representation(storage: list[Product]) -> str: @@ -91,5 +104,15 @@ 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: list[list[str]] = [] + rows.append(list(TABLE_HEADERS)) + for product in storage: + rows.append([str(val) for val in product]) + widths = column_width(rows) + table_lines = [ + formatted_row(rows[0], widths), + rows_separator(widths), + ] + for row in rows[1:]: + table_lines.append(formatted_row(row, widths)) + return "\n".join(table_lines)