How to use decorators to decorate functions in Python?

6 months ago

2 minutes

In Python, decorators are functions that take another function as input and return a new function. By using decorators, additional features or logic can be added to a function without modifying its original code.

Here is a simple example demonstrating how to use decorators to decorate functions:

# 定义一个装饰器函数
def my_decorator(func):
    def wrapper():
        print("Before calling the function")
        func()
        print("After calling the function")
    return wrapper

# 使用装饰器来装饰函数
@my_decorator
def say_hello():
    print("Hello!")

# 调用装饰后的函数
say_hello()

In the example above, my_decorator is a decorator function that takes a function as an argument and returns a new function called wrapper. In the wrapper function, we can add additional logic before and after calling the original function. By adding @my_decorator above the say_hello function, we pass the say_hello function to the my_decorator decorator function and assign the returned new function to say_hello, thus decorating the say_hello function.

When we call the say_hello function, we are actually calling the decorated wrapper function, which will print “Before calling the function” before and “After calling the function” after printing “Hello!” This way, we have successfully decorated the function using a decorator.