python学习之老男孩python全栈第九期_day012知识点总结

# def wrapper(f):
#     def inner(*args,**kwargs):
#         print('在被装饰的函数执行之前做的事')
#         res = f(*args,**kwargs)
#         print('在被装饰的函数执行之后做的事')
#         return res
#     return inner
# @wrapper            # holiday = wrapper(holiday)    这时holiday == inner
# def holiday(day):
#     print('全体放假%s天'%day)
#     return '好开心'
# ret = holiday(3)
# print(ret)

# def outer(*args,**kwargs):
#     print(args,kwargs)
#     print(*args)
#     def inner(*args):
#         print('inner:', args)
#     inner(*args)
# outer(1,2,3,4,a = 1,b = 2)

# 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 (查看函数的注释)


# from functools import wraps
# def wrapper(f):     # f = holiday
#     @wraps(f)                               # 加上这句话之后, holiday 就是holiday 不是inner了
#     def inner(*args,**kwargs):
#         print('在被装饰的函数执行之前做的事')
#         res = f(*args,**kwargs)
#         print('在被装饰的函数执行之后做的事')
#         return res
#     return inner
# @wrapper            # holiday = wrapper(holiday)    这时holiday == inner  ，这时还没加上面那句话
# def holiday(day):
#     print('全体放假%s天'%day)
#     return '好开心'
# ret = holiday(3)
# print(holiday.__name__)     # 输出inner，加了上面那句话之后输出 holiday

# ---------------------------------------------------------------------------------------------------- #

# 带参数的装饰器

# 500个函数
#
# import time
# FLAG = True
# def timmer_out(flag):
#     '''
#     计算机函数执行时间
#     :param flag:flag为真时,运行这个函数,为假时不运行
#     :return:
#     '''
#     def timmer(func):
#         def inner(*args,**kwargs):
#             if FLAG:
#                 start_time = time.time()
#                 ret = func(*args,**kwargs)
#                 end_time = time.time()
#                 print(end_time - start_time)
#                 return ret
#             else:
#                 ret = func(*args, **kwargs)
#                 return ret
#         return inner
#     return timmer
# @timmer_out(FLAG)           # 先调用timmer_out(FLAG)，返回的结果为timmer, 加了@ 之后就等于 @timmer,就等于wahaha = timmer(wahaha)
# # 上个式子等价于：
# # timmer = timmer_out(FLAG)
# #@timmer
#
# def wahaha():
#     time.sleep(0.1)
#     print('娃哈哈')
# @timmer_out(FLAG)
# def erguotou():
#     time.sleep(0.1)
#     print('二锅头')
# wahaha()
# erguotou()


# 多个装饰器装饰一个函数

#
# def wrapper1(func):     # func --> f
#     def inner1():
#         print('wrapper1,before func')
#         func()      # f
#         print('wrapper1,after func')
#     return inner1
#
# def wrapper2(func):     # func --> inner1
#     def inner2():
#         print('wrapper2, before func')
#         func()      # 其实是 inner1()
#         print('wrapper2, after func')
#     return inner2
#
# @wrapper2   # f = wrapper2(f) --> wrapper2(inner1), 返回的inner2，故 f == inner2
# @wrapper1   # f = wrapper1(f) 返回的inner1，故 f == inner1
#
# # 先找最近的函数,wrapper2没找到, wrapper1先找的f()，然后wrapper2又找的
# def f():
#     print('in f')
#
# f() # --> inner2()

# ---------------------------------------------------------------------------------- #
# 三个

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 and 计算这个函数的执行时间