From 8d824458e70a6593f08702f6e052e299c78aada7 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Thu, 24 Sep 2026 17:52:10 +0300
Subject: [PATCH 01/11] Solve task 1

---
 src/part1/constants.py | 16 ++++++++--------
 src/part1/snowflake.py | 30 ++++++++++++++++++++++++------
 2 files changed, 32 insertions(+), 14 deletions(-)

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)
+    )

From 300a25afc903531c736f0f39a196e0cbcac4c5e8 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Fri, 2 Oct 2026 23:54:56 +0300
Subject: [PATCH 02/11] =?UTF-8?q?=D0=92=D1=8B=D0=BF=D0=BE=D0=BB=D0=BD?=
 =?UTF-8?q?=D0=B8=D0=BBa=20=D0=B7=D0=B0=D0=B4=D0=B0=D0=BD=D0=B8=D0=B5=202?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 pl-001-python-basics-task |  1 +
 src/part1/lesson 4.py     | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 160000 pl-001-python-basics-task
 create mode 100644 src/part1/lesson 4.py

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/lesson 4.py b/src/part1/lesson 4.py
new file mode 100644
index 00000000..4d09c809
--- /dev/null
+++ b/src/part1/lesson 4.py	
@@ -0,0 +1,15 @@
+def merge_sorted_lists(first: list[int], second: list[int]) -> list[int]:
+    a=[]
+    for i in range(len(first)):
+        a.append(first[i])
+    for j in range(len(second)):
+        a.append(second[j])
+    return sorted(a) 
+assert merge_sorted_lists([], []) == []
+assert merge_sorted_lists([1, 2], []) == [1, 2]
+assert merge_sorted_lists([], [1, 2]) == [1, 2]
+assert merge_sorted_lists([1, 2, 3], [4, 5]) == [1, 2, 3, 4, 5]
+assert merge_sorted_lists([4, 5], [1, 2, 3]) == [1, 2, 3, 4, 5]
+assert merge_sorted_lists([1, 1], [1]) == [1, 1, 1]
+
+print("All tests passed")
\ No newline at end of file

From f82f25a0c7cc7c0134e2bb2ab986f399f8a315f3 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Thu, 8 Oct 2026 04:57:37 +0300
Subject: [PATCH 03/11] =?UTF-8?q?=D0=A1=D0=B4=D0=B5=D0=BB=D0=B0=D0=BB?=
 =?UTF-8?q?=D0=B0=20=D1=87=D0=B0=D1=81=D1=82=D1=8C=203?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/part1/{lesson 4.py => lesson_4.py} |  0
 src/part3/crud.py                      | 59 ++++++++++++++++++++---
 src/part3/run_admin.py                 | 65 +++++++++++++++++++++++---
 src/part3/storage.py                   |  8 ++--
 src/part3/utils.py                     | 43 +++++++++++++----
 5 files changed, 150 insertions(+), 25 deletions(-)
 rename src/part1/{lesson 4.py => lesson_4.py} (100%)

diff --git a/src/part1/lesson 4.py b/src/part1/lesson_4.py
similarity index 100%
rename from src/part1/lesson 4.py
rename to src/part1/lesson_4.py
diff --git a/src/part3/crud.py b/src/part3/crud.py
index 68811d7e..b9ba934c 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 +130,28 @@ 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 +168,9 @@ 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..614ad226 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 <name...> <price> <quantity>  add a product, print its new id
+  read <id>                     print the product with that id
+  update <id> <name...> <price> <quantity>  overwrite that product's fields
+  delete <id>                   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 +78,9 @@ 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 +104,51 @@ 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])
+        result = update_product(storage, product_id, (name, price, quantity))
+        print_result(result)
+    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..040662a8 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 +98,25 @@ 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)

From 51eaf8eb0610ab5a4fa0360252d02072001317f7 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Thu, 8 Oct 2026 05:10:21 +0300
Subject: [PATCH 04/11] =?UTF-8?q?=D1=81=D0=B4=D0=B5=D0=BB=D0=B0=D0=BB?=
 =?UTF-8?q?=D0=B0=20=D1=87=D0=B0=D1=81=D1=82=D1=8C=203(=D0=BF=D0=BE=D0=BF?=
 =?UTF-8?q?=D1=8B=D1=82=D0=BA=D0=B0=202)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/part1/lesson_4.py | 15 ---------------
 1 file changed, 15 deletions(-)
 delete mode 100644 src/part1/lesson_4.py

diff --git a/src/part1/lesson_4.py b/src/part1/lesson_4.py
deleted file mode 100644
index 4d09c809..00000000
--- a/src/part1/lesson_4.py
+++ /dev/null
@@ -1,15 +0,0 @@
-def merge_sorted_lists(first: list[int], second: list[int]) -> list[int]:
-    a=[]
-    for i in range(len(first)):
-        a.append(first[i])
-    for j in range(len(second)):
-        a.append(second[j])
-    return sorted(a) 
-assert merge_sorted_lists([], []) == []
-assert merge_sorted_lists([1, 2], []) == [1, 2]
-assert merge_sorted_lists([], [1, 2]) == [1, 2]
-assert merge_sorted_lists([1, 2, 3], [4, 5]) == [1, 2, 3, 4, 5]
-assert merge_sorted_lists([4, 5], [1, 2, 3]) == [1, 2, 3, 4, 5]
-assert merge_sorted_lists([1, 1], [1]) == [1, 1, 1]
-
-print("All tests passed")
\ No newline at end of file

From be4c522a3cd713f854bbb47090d5ec5443bf5467 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Thu, 8 Oct 2026 05:14:44 +0300
Subject: [PATCH 05/11] =?UTF-8?q?=D1=87=D0=B0=D1=81=D1=82=D1=8C=203(=D0=BF?=
 =?UTF-8?q?=D0=BE=D0=BF=D1=8B=D1=82=D0=BA=D0=B0=203)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/part3/crud.py      |  5 ++---
 src/part3/run_admin.py |  1 -
 src/part3/utils.py     | 16 +++++++++-------
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/part3/crud.py b/src/part3/crud.py
index b9ba934c..01eef2e4 100644
--- a/src/part3/crud.py
+++ b/src/part3/crud.py
@@ -96,7 +96,7 @@ def read_product(storage: list[Product], product_id: int) -> Product | None:
         printed in that case).
     """
     # TODO: реализуйте функцию (используйте своё решение части 2)
-    for product in  storage:
+    for product in storage:
         if product[PRODUCT_ID_INDEX] == product_id:
             return product
     print(f"no product with id {product_id}")
@@ -144,8 +144,7 @@ def update_product(
         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):
+        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)
diff --git a/src/part3/run_admin.py b/src/part3/run_admin.py
index 614ad226..dd326feb 100644
--- a/src/part3/run_admin.py
+++ b/src/part3/run_admin.py
@@ -82,7 +82,6 @@ def print_result(result: object) -> None:
         print(result)
 
 
-
 def run_command(storage: list[Product], line: str) -> bool:
     """Parse one console line and carry out the command it names.
 
diff --git a/src/part3/utils.py b/src/part3/utils.py
index 040662a8..136bfc33 100644
--- a/src/part3/utils.py
+++ b/src/part3/utils.py
@@ -100,12 +100,14 @@ def get_storage_str_representation(storage: list[Product]) -> str:
     # TODO: реализуйте функцию
     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])
-        ))
+        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):
@@ -118,5 +120,5 @@ def get_storage_str_representation(storage: list[Product]) -> str:
     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  
+    result_lines = [header_line, separator_line] + data_lines
     return "\n".join(result_lines)

From 49c76a08444f72d77f17745fed8c043f6bcbe089 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Thu, 8 Oct 2026 05:19:21 +0300
Subject: [PATCH 06/11] =?UTF-8?q?=D1=87=D0=B0=D1=81=D1=82=D1=8C=203=20(?=
 =?UTF-8?q?=D0=BF=D0=BE=D0=BF=D1=8B=D1=82=D0=BA=D0=B0=204)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/part3/run_admin.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/part3/run_admin.py b/src/part3/run_admin.py
index dd326feb..d4ee4b70 100644
--- a/src/part3/run_admin.py
+++ b/src/part3/run_admin.py
@@ -136,8 +136,8 @@ def run_command(storage: list[Product], line: str) -> bool:
         name = " ".join(parts[2:-2])
         price = Decimal(parts[-2])
         quantity = int(parts[-1])
-        result = update_product(storage, product_id, (name, price, quantity))
-        print_result(result)
+        updated = update_product(storage, product_id, (name, price, quantity))
+        print_result(updated)
     else:
         print(f"'{line}' is not a command")
 

From 942fe698c7d52b28be9524fc82ee95d58833baf0 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Sun, 1 Nov 2026 22:47:36 +0300
Subject: [PATCH 07/11] =?UTF-8?q?=D1=81=D0=B4=D0=B5=D0=BB=D0=B0=D0=BB?=
 =?UTF-8?q?=D0=B0=20=D0=B7=D0=B0=D0=B4=D0=B0=D0=BD=D0=B8=D0=B5=204?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/part4/cart.py      | 40 ++++++++++++++++++++--
 src/part4/crud.py      | 65 ++++++++++++++++++++++++++++++-----
 src/part4/run_admin.py | 78 ++++++++++++++++++++++++++++++++++++++----
 src/part4/storage.py   |  7 ++--
 src/part4/utils.py     | 42 ++++++++++++++++++-----
 5 files changed, 202 insertions(+), 30 deletions(-)

diff --git a/src/part4/cart.py b/src/part4/cart.py
index aed9bb72..cf684749 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..d42f542b 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 +103,11 @@ 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 +148,30 @@ 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 +195,12 @@ 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..685d1e81 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 <name...> <price> <quantity>  add a product, print its new id
+  read <id>                     print the product with that id
+  update <id> <name...> <price> <quantity>  overwrite that product's fields
+  delete <id>                   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 +106,57 @@ 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..a0fa9b53 100644
--- a/src/part4/storage.py
+++ b/src/part4/storage.py
@@ -32,7 +32,6 @@
 functions in :mod:`src.part4.crud` keep the two in sync on every
 successful create, update and delete.
 """
-
 from typing import Any, Final
 
 
@@ -40,6 +39,6 @@
 
 # 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..88e2eb1c 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 +97,30 @@ 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)
+    

From 8af4a6e30f7ed30557152eeb162aff645f1d77cb Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Sun, 1 Nov 2026 23:07:55 +0300
Subject: [PATCH 08/11] =?UTF-8?q?4=20=D1=87=D0=B0=D1=81=D1=82=D1=8C(=D0=BF?=
 =?UTF-8?q?=D0=BE=D0=BF=D1=8B=D1=82=D0=BA=D0=B0=202)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/part4/cart.py      |  2 +-
 src/part4/crud.py      |  6 ++----
 src/part4/run_admin.py |  9 ++++-----
 src/part4/storage.py   |  1 +
 src/part4/utils.py     | 17 +++++++++--------
 5 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/src/part4/cart.py b/src/part4/cart.py
index cf684749..8b7b5e79 100644
--- a/src/part4/cart.py
+++ b/src/part4/cart.py
@@ -99,7 +99,7 @@ def remove_from_cart(
     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(
diff --git a/src/part4/crud.py b/src/part4/crud.py
index d42f542b..c0caed9f 100644
--- a/src/part4/crud.py
+++ b/src/part4/crud.py
@@ -107,7 +107,6 @@ def read_product(storage: dict[str, Product], product_id: str) -> Product | None
         print(f"no product with id {product_id}")
         return None
     return storage[product_id]
-    
 
 
 def update_product(
@@ -167,7 +166,7 @@ def update_product(
         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]
 
@@ -198,9 +197,8 @@ def delete_product(
     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 685d1e81..9e3aed66 100644
--- a/src/part4/run_admin.py
+++ b/src/part4/run_admin.py
@@ -109,7 +109,7 @@ def run_command(
     parts = line.split()
     if not parts:
         return True
-        
+
     command = parts[0]
 
     match command:
@@ -136,7 +136,7 @@ def run_command(
             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)
@@ -148,15 +148,14 @@ def run_command(
             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 a0fa9b53..a25f6253 100644
--- a/src/part4/storage.py
+++ b/src/part4/storage.py
@@ -32,6 +32,7 @@
 functions in :mod:`src.part4.crud` keep the two in sync on every
 successful create, update and delete.
 """
+
 from typing import Any, Final
 
 
diff --git a/src/part4/utils.py b/src/part4/utils.py
index 88e2eb1c..c0a0cbfa 100644
--- a/src/part4/utils.py
+++ b/src/part4/utils.py
@@ -99,12 +99,14 @@ def get_storage_str_representation(storage: dict[str, Product]) -> str:
     # TODO: реализуйте функцию (используйте своё решение части 3)
     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])
-        ))
+        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):
@@ -112,7 +114,7 @@ def get_storage_str_representation(storage: dict[str, Product]) -> str:
 
     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) + "|"
 
@@ -123,4 +125,3 @@ def get_storage_str_representation(storage: dict[str, Product]) -> str:
 
     result_lines = [header_line, separator_line] + data_lines
     return "\n".join(result_lines)
-    

From 8b03f627a48de9d24d031fe12e5721b806cfac8d Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Wed, 4 Nov 2026 22:52:58 +0300
Subject: [PATCH 09/11] Part 2

---
 src/part2/cart.py    | 83 ++++++++++++++++++++++++++++++++++++++++----
 src/part2/crud.py    | 52 +++++++++++++++++++++++----
 src/part2/storage.py |  9 +++--
 src/part2/utils.py   |  9 +++--
 4 files changed, 130 insertions(+), 23 deletions(-)

diff --git a/src/part2/cart.py b/src/part2/cart.py
index 063f9aea..4ef6950f 100644
--- a/src/part2/cart.py
+++ b/src/part2/cart.py
@@ -11,22 +11,45 @@
 
 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,
     Product,
 )
 
-
 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 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(
     storage: list[Product],
     cart: list[CartLine],
@@ -54,7 +77,30 @@ 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 +132,29 @@ 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..037682f6 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 +59,20 @@ 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 +88,12 @@ 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 +120,18 @@ 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 +148,11 @@ 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..2c0620b2 100644
--- a/src/part2/storage.py
+++ b/src/part2/storage.py
@@ -21,14 +21,13 @@
 from decimal import Decimal
 from typing import Final
 
-
 type Product = tuple[int, str, Decimal, int]
 
 # TODO: задайте позиции полей внутри кортежа Product
 PRODUCT_ID_INDEX: Final = 0
-NAME_INDEX: Final = 0
-PRICE_INDEX: Final = 0
-QUANTITY_INDEX: Final = 0
+NAME_INDEX: Final = 1
+PRICE_INDEX: Final = 2
+QUANTITY_INDEX: Final = 3
 
 # TODO: задайте идентификатор первого товара в пустом хранилище
-PRODUCT_ID_MIN: Final[int] = 0
+PRODUCT_ID_MIN: Final[int] = 1
diff --git a/src/part2/utils.py b/src/part2/utils.py
index 11bd7a76..35d91c1a 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:
@@ -26,4 +25,4 @@ 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)

From 9a6628ead23233c181d6771fa9d45a73b48a9fc5 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Wed, 4 Nov 2026 23:03:42 +0300
Subject: [PATCH 10/11] Part2 fixes

---
 src/part2/cart.py    | 1 +
 src/part2/storage.py | 1 +
 src/part2/utils.py   | 1 +
 3 files changed, 3 insertions(+)

diff --git a/src/part2/cart.py b/src/part2/cart.py
index 4ef6950f..e15fcf1a 100644
--- a/src/part2/cart.py
+++ b/src/part2/cart.py
@@ -19,6 +19,7 @@
     Product,
 )
 
+
 type CartLine = tuple[int, int]
 
 # TODO: задайте позиции полей внутри кортежа CartLine
diff --git a/src/part2/storage.py b/src/part2/storage.py
index 2c0620b2..35821c5f 100644
--- a/src/part2/storage.py
+++ b/src/part2/storage.py
@@ -21,6 +21,7 @@
 from decimal import Decimal
 from typing import Final
 
+
 type Product = tuple[int, str, Decimal, int]
 
 # TODO: задайте позиции полей внутри кортежа Product
diff --git a/src/part2/utils.py b/src/part2/utils.py
index 35d91c1a..2b6aa266 100644
--- a/src/part2/utils.py
+++ b/src/part2/utils.py
@@ -9,6 +9,7 @@
 from decimal import ROUND_HALF_UP, Decimal
 from typing import Final
 
+
 # TODO: задайте число знаков после запятой и шаг квантования
 PRICE_PRECISION: Final[int] = 2
 PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION)

From 9eaac7d2aab926ffda42176b366dca2c99083536 Mon Sep 17 00:00:00 2001
From: Darina ramazanova <darinaramaz4nova@yandex.ru>
Date: Wed, 4 Nov 2026 23:05:40 +0300
Subject: [PATCH 11/11] Part2 fixees

---
 src/part2/cart.py | 13 +++++++------
 src/part2/crud.py | 13 +++++--------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/src/part2/cart.py b/src/part2/cart.py
index e15fcf1a..4d5df33d 100644
--- a/src/part2/cart.py
+++ b/src/part2/cart.py
@@ -26,8 +26,9 @@
 LINE_PRODUCT_ID_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
@@ -37,20 +38,21 @@ def find_cart_line(cart: list[CartLine], product_id: int) -> CartLine | 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 
+                return None
             else:
                 new_line = (product_id, new_quantity)
                 cart[i] = new_line
                 return new_line
     return None
 
+
 def add_to_cart(
     storage: list[Product],
     cart: list[CartLine],
@@ -103,7 +105,6 @@ def add_to_cart(
         return new_line
 
 
-
 def remove_from_cart(
     storage: list[Product],
     cart: list[CartLine],
@@ -149,7 +150,7 @@ def remove_from_cart(
     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)
diff --git a/src/part2/crud.py b/src/part2/crud.py
index 037682f6..ee9ea22a 100644
--- a/src/part2/crud.py
+++ b/src/part2/crud.py
@@ -65,14 +65,13 @@ def create_product(
         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:
@@ -91,7 +90,7 @@ def read_product(storage: list[Product], product_id: int) -> Product | None:
     for product in storage:
         if product[PRODUCT_ID_INDEX] == product_id:
             return product
-            
+
     print(f"no product with id {product_id}")
     return None
 
@@ -128,10 +127,9 @@ def update_product(
             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:
@@ -152,7 +150,6 @@ def delete_product(storage: list[Product], product_id: int) -> int | None:
         if product[PRODUCT_ID_INDEX] == product_id:
             del storage[i]
             return product_id
-            
+
     print(f"no product with id {product_id}")
     return None
-