python学习第十二天 装饰器进阶

1.wraps

from functools import wraps
def wrapper(func):  #func = holiday
    @wraps(func)
    def inner(*args,**kwargs):
        print('在被装饰的函数执行之前做的事')
        ret = func(*args,**kwargs)
        print('在被装饰的函数执行之后做的事')
        return ret
    return inner

@wrapper   #holiday = wrapper(holiday)
def holiday(day):
    '''这是一个放假通知'''
    print('全体放假%s天'%day)
    return '好开心'

print(holiday.__name__)
print(holiday.__doc__)
ret = holiday(3)   #inner
print(ret)


# def wahaha():
#     '''
#     一个打印娃哈哈的函数
#     :return:
#     '''
#     print('娃哈哈')

# print(wahaha.__name__) #查看字符串格式的函数名
# print(wahaha.__doc__)  #document

2.装饰器进阶

#带参数的装饰器
#500个函数
# import time
# FLAGE = False
# def timmer_out(flag):
#     def timmer(func):
#         def inner(*args,**kwargs):
#             if flag:
#                 start = time.time()
#                 ret = func(*args,**kwargs)
#                 end = time.time()
#                 print(end-start)
#                 return ret
#             else:
#                 ret = func(*args, **kwargs)
#                 return ret
#         return inner
#     return timmer
# # timmer = timmer_out(FLAGE)
# @timmer_out(FLAGE)    #wahaha = timmer(wahaha)
# def wahaha():
#     time.sleep(0.1)
#     print('wahahahahahaha')
#
# @timmer_out(FLAGE)
# def erguotou():
#     time.sleep(0.1)
#     print('erguotoutoutou')

# wahaha()
# erguotou()

#多个装饰器装饰一个函数
def wrapper1(func):
    def inner1():
        print('wrapper1 ,before func')
        ret = func()
        print('wrapper1 ,after func')
        return ret
    return inner1

def wrapper2(func):
    def inner2():
        print('wrapper2 ,before func')
        ret = func()
        print('wrapper2 ,after func')
        return ret
    return inner2

def wrapper3(func):
    def inner3():
        print('wrapper3 ,before func')
        ret = func()
        print('wrapper3 ,after func')
        return ret
    return inner3

@wrapper3
@wrapper2
@wrapper1
def f():
    print('in f')
    return '哈哈哈'

print(f())

#记录用户的登录情况
#计算这个函数的执行时间