函数作装饰器 ，类做装饰器

函数作装饰器 ，类做装饰器

一.用类写装饰器

"""
用类写装饰器
func = Decorator(func)
func('abc',18)
"""

class Decorator(object):
def __init__(self, f):
self.f = f
def __call__(self,*args,**kwargs):
print("decorator start")
self.f(*args,**kwargs)
print("decorator end")

@Decorator
def func(name,age):
print("{0}\' is {1}".format(name,age))
print("func")

func('abc',18)

二.用函数写装饰器

'''

用函数写装饰器
func1 = Decorator1(func)
func1('abc',18)
'''

def Decorator1(f):
def wrapper(*args,**kwargs):
print("decorator start")
f(*args, **kwargs)
print("decorator end")
return wrapper

@Decorator1
def func1(name,age):
print("{0}\' is {1}".format(name, age))

func1('abc',18)

三.消除装饰器对函数的影响

def Decorator1(f):

    def wrapper(*args,**kwargs):
        print("decorator start")
        f(*args, **kwargs)
        print("decorator end")
    return wrapper

@Decorator1
def func1(name,age):
    print("{0}\' is {1}".format(name, age))

func1('abc',18)

print("function \'s name is {}".format(func1.__name__))

输出为：

decorator start
abc' is 18
decorator end
function 's name is wrapper

 

这是由于装饰后的func其实相当于 func= Decorator1(func) 

而 func.__name ,也相当于Decorator1(func) .__name__

消除这种影响的办法是 使用  functools 工具包中的 wraps 装饰器

from functools import wraps
def Decorator1(f):
    @wraps(f)
    def wrapper(*args,**kwargs):
        print("decorator start")
        f(*args, **kwargs)
        print("decorator end")
    return wrapper

@Decorator1
def func1(name,age):
    print("{0}\' is {1}".format(name, age))

func1('abc',18)
print("function \'s name is {}".format(func1.__name__))

输入为：

decorator start
abc' is 18
decorator end
function 's name is func1

消除后显示正常