伟大的Python装饰器示例

Posted 2021-02-25

def decorator_maker_with_arguments(decorator_arg1, decorator_arg2) :
 
    print "I make decorators ! And I accept arguments:", decorator_arg1, decorator_arg2
 
    def my_decorator(func) :
        # The hability to pass arguments here is a gift from closures.
        # If you are not confortable with closures, you can assume it's ok,
        # or read : http://stackoverflow.com/questions/13857/can-you-explain-closures-as-they-relate-to-python
        print "I am the decorator. Somehow you passed me arguments:", decorator_arg1, decorator_arg2
 
        # Don't confuse decorator arguments and function arguments !
        def wrapped(function_arg1, function_arg2) :
            print "I am the wrapper arround the decorated function.",
                  "
I can access all the variables",
                  "
	- from the decorator:", decorator_arg1, decorator_arg2,
                  "
	- from the function call:", function_arg1, function_arg2,
                  "
Then I can pass them to the decorated function"
            return func(function_arg1, function_arg2)
 
        return wrapped
 
    return my_decorator
 
@decorator_maker_with_arguments("Leonard", "Sheldon")
def decorated_function_with_arguments(function_arg1, function_arg2) :
    print "I am the decorated function and only knows about my arguments :",
          function_arg1, function_arg2
 
decorated_function_with_arguments("Rajesh", "Howard")
#outputs:
#I make decorators ! And I accept arguments: Leonard Sheldon
#I am the decorator. Somehow you passed me arguments: Leonard Sheldon
#I am the wrapper arround the decorated function. 
#I can access all the variables 
#   - from the decorator: Leonard Sheldon 
#   - from the function call: Rajesh Howard 
#Then I can pass them to the decorated function
#I am the decorated function and only knows about my arguments : Rajesh Howard