def my_decorator(func): def wrapper(): print("Something is happening before the function is called.") func() print("Something is happening after the function is called.") return wrapper def say_whee(): print("Whee!") say_whee = my_decorator(say_whee)
>>> say_whee() Something is happening before the function is called. Whee! Something is happening after the function is called.
Instead, Python allows you to use decorators in a simpler way with the @ symbol, sometimes called the “pie” syntax. The following example does the exact same thing as the first decorator example:
def my_decorator(func): def wrapper(): print("Something is happening before the function is called.") func() print("Something is happening after the function is called.") return wrapper @my_decorator def say_whee(): print("Whee!")
More: https://realpython.com/primer-on-python-decorators/
原文：https://www.cnblogs.com/Answer1215/p/12994456.html