# import functools

**[import functools](https://docs.python.org/3/library/functools.html)** is a Python import that provides functional programming tools: function caching, partial application, and wrapping functions with decorators.

## Example

```python
# Python
# description: cache function results, partial application

from functools import lru_cache, partial, wraps

# Cache function results (memoization)
@lru_cache(maxsize=128)
def fibonacci(n):
    if n < 2:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

print(fibonacci(10))  # Fast due to caching

# Partial application - fix some arguments
def multiply(a, b):
    return a * b

double = partial(multiply, 2)
print(double(5))  # 10

# Decorator that preserves metadata
def timer(func):
    @wraps(func)
    def wrapper(*args, **kwargs):
        print(f"Calling {func.__name__}")
        return func(*args, **kwargs)
    return wrapper

@timer
def greet(name):
    return f"Hello, {name}"

print(greet("Alice"))
```

## Common functions

- `@lru_cache(maxsize)`: cache function results
- `@cache`: unbounded cache (Python 3.9+)
- `partial(func, *args)`: fix some arguments
- `@wraps(wrapped)`: preserve function metadata in decorators
- `reduce(function, iterable)`: apply function cumulatively