⏱️ 2 min 55 sec read

Using Decorators

8th Mar 2023

In Python, a decorator is a way to modify or extend the behavior of a function or class without changing its source code. Decorators are a powerful tool for adding functionality to existing code, and they are especially useful when you want to apply the same behavior to multiple functions or classes.

How Decorators Work

In Python, functions are first-class objects, which means they can be assigned to variables, passed as arguments to other functions, and returned as values from other functions. This makes it possible to define a decorator function that takes another function as an argument, modifies its behavior in some way, and then returns the modified function.

Here's an example of a simple decorator that adds logging to a function:

def log_function(func):
    def wrapper(*args, **kwargs):
        result = func(*args, **kwargs)
        print(f"Called {func.__name__} with args {args} and kwargs {kwargs}. Result: {result}")
        return result
    return wrapper

@log_function
def my_function(x, y):
    return x + y

In this example, log_function is a decorator that takes a function as an argument and returns a new function that logs the arguments and result of the original function. The @log_function syntax is a shorthand way of applying the decorator to the my_function function.

Using Decorators with Classes

Decorators can also be used with classes in Python. Here's an example of a decorator that adds logging to a class method:

def log_method(func):
    def wrapper(*args, **kwargs):
        result = func(*args, **kwargs)
        print(f"Called {func.__name__} with args {args} and kwargs {kwargs}. Result: {result}")
        return result
    return wrapper

class MyClass:
    @log_method
    def my_method(self, x, y):
        return x + y

In this example, log_method is a decorator that takes a method as an argument and returns a new method that logs the arguments and result of the original method. The @log_method syntax is a shorthand way of applying the decorator to the my_method method.

Learning More About Decorators

Decorators are a powerful tool for extending the functionality of Python functions and classes. If you want to learn more about decorators, here are some resources to get you started:

Thanks for reading! Let me know if you have any questions or suggestions for future blog posts.