What are some practical use cases for decorators in Python?

What are some practical use cases for decorators in Python?

Decorators in Python are used to modify the behavior of functions or methods. Common use cases include logging, access control, and memoization.

Can you give me an example of a logging decorator?

Sure! Here's a simple logging decorator:

def log_function_call(func):
    def wrapper(*args, **kwargs):
        print(f'Calling {func.__name__} with arguments {args} and {kwargs}')
        return func(*args, **kwargs)
    return wrapper

How about a decorator for access control?

An access control decorator can check user permissions before allowing a function to execute. Here's a basic example:

def requires_permission(permission):
    def decorator(func):
        def wrapper(user, *args, **kwargs):
            if user.has_permission(permission):
                return func(user, *args, **kwargs)
            else:
                raise PermissionError('Access denied')
        return wrapper
    return decorator

What is memoization and how can I implement it with a decorator?

Memoization is an optimization technique to cache results of expensive function calls. Here's a simple memoization decorator:

def memoize(func):
    cache = {}
    def wrapper(*args):
        if args not in cache:
            cache[args] = func(*args)
        return cache[args]
    return wrapper