💻 Практические примеры

Пример 1. Сумма чисел списка

def recursive_sum(numbers: list) -> float:
    """Return the sum of all numbers in a list recursively."""
    if not isinstance(numbers, list):
        raise TypeError("Argument must be a list")
    if not numbers:
        return 0

    head = numbers[0]
    if not isinstance(head, (int, float)):
        raise TypeError(f"All elements must be numbers, got {type(head).__name__}")
    return head + recursive_sum(numbers[1:])


numbers = [1, 2, 3, 4, 5]
try:
    print(recursive_sum(numbers))
except (TypeError, ValueError) as e:
    print(f"Ошибка: {e}")

Пример 2. Реверс строки

def reverse_string(text: str) -> str:
    """Return the reversed string using recursion."""
    if not isinstance(text, str):
        raise TypeError("Argument must be a string")
    if len(text) <= 1:
        return text
    return text[-1] + reverse_string(text[:-1])


text = "recursion"
try:
    print(reverse_string(text))
except TypeError as e:
    print(f"Ошибка: {e}")

Пример 3. Глубина вложенности списка

def list_depth(nested_list: list) -> int:
    """Return the maximum nesting depth of a list."""
    if not isinstance(nested_list, list):
        raise TypeError("Argument must be a list")

    max_inner = 0
    for item in nested_list:
        if isinstance(item, list):
            max_inner = max(max_inner, list_depth(item))
    return 1 + max_inner


nested_list = [1, [2, [3, [4, [5]]]], 6, [[7, 8], 9]]
try:
    print("Максимальная глубина:", list_depth(nested_list))
except TypeError as e:
    print(f"Ошибка: {e}")

Пример 4. Сумма продаж по дереву отделов

def total_sales(department: dict) -> int | float:
    """Return the total sales of a department and all its sub-departments."""
    if not isinstance(department, dict):
        raise TypeError("Department must be a dict")

    sales = department.get("sales", 0)
    total = sales
    sub_departments = department.get("sub_departments")

    if sub_departments is not None:
        if not isinstance(sub_departments, list):
            raise TypeError("sub_departments must be a list")
        for sub in sub_departments:
            if not isinstance(sub, dict):
                raise TypeError("Each sub_department must be a dict")
            total += total_sales(sub)

    return total


company_structure = {
    "dept_name": "Head Office",
    "sales": 100,
    "sub_departments": [
        {
            "dept_name": "Sales Department",
            "sales": 200,
            "sub_departments": [
                {"dept_name": "B2B Sales", "sales": 120}
            ]
        },
        {
            "dept_name": "IT Department",
            "sales": 150,
            "sub_departments": [
                {
                    "dept_name": "DevOps",
                    "sales": 300,
                    "sub_departments": [
                        {"dept_name": "Cloud Infrastructure", "sales": 180}
                    ]
                },
                {"dept_name": "QA Department", "sales": 90}
            ]
        }
    ]
}

try:
    print("Общая сумма продаж:", total_sales(company_structure))
except TypeError as e:
    print(f"Ошибка: {e}")

Пример 5. Читабельный формат словаря

def flatten_dict(data: dict, prefix: str = "") -> dict:
    """Convert a nested dict into a flat dict with dot-separated keys."""
    if not isinstance(data, dict):
        raise TypeError("Argument must be a dict")

    result = {}
    for key, value in data.items():
        full_key = f"{prefix}.{key}" if prefix else key
        if isinstance(value, dict):
            result.update(flatten_dict(value, full_key))
        else:
            result[full_key] = value
    return result


data = {
    "user": {
        "id": 123,
        "info": {
            "name": "Alice",
            "location": {
                "city": "Berlin",
                "coordinates": {"lat": 52.52, "lon": 13.405}
            },
            "hobby": ["swimming", "drawing"]
        }
    },
    "score": 95
}

flat = flatten_dict(data)
print("Данные для анализа:")
for key, value in flat.items():
    print(f"{key} : {value}")

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