之前在学习flash的时候用到过python的装饰器，但是却不知道具体的原理，特此花费一些时间学习 一下装饰器的知识。
1.装饰器就是python的函数，使用方式: @函数的名称
简单的就是把一个函数作为参数传递给另外一个函数，所以另外的使用方式： 函数1 = 函数2(函数3)
2.一个不带参数的装饰器并使用: @函数名
不带参数的装饰器
def myfunc(func):
print("myfunc before")
func()
print("myfunc after")
@myfunc
def funcs(a):
print("this is funcs")
funcs() # 在调用funcs函数时，就会先把funcs函数地址传递给 myfunc函数的func，执行func的动作就相当于执行funcs函数
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装饰器函数引用被装饰函数的参数案例
def myfunc(func):
def warpper(*args,**kwargs) # *args, **kwargs用于接收func的参数 warpper函数和funcs的函数地址是一样的
print("myfunc before")
func(*args,**kwargs)
print("myfunc after")
@myfunc
def funcs(a):
print(a)
funcs(1)
3.带参数的装饰器: @函数名("","")
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):
# 这里传递参数的能力是借鉴了 closures.
# 如果对closures感到困惑可以看看下面这个:
# 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
# 不要忘了装饰器参数和函数参数!
def wrapped(function_arg1, function_arg2) :
print ("I am the wrapper around the decorated function.\n"
"I can access all the variables\n"
"\t- from the decorator: {0} {1}\n"
"\t- from the function call: {2} {3}\n"
"Then I can pass them to the decorated function"
.format(decorator_arg1, decorator_arg2,
function_arg1, function_arg2))
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: {0}"
" {1}".format(function_arg1, function_arg2))
decorated_function_with_arguments("Rajesh", "Howard")
#输出:
#I make decorators! And I accept arguments: Leonard Sheldon
#I am the decorator. Somehow you passed me arguments: Leonard Sheldon
#I am the wrapper around 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