装饰器进阶
1、使用了装饰器函数,还能通过__name__、__doc__查看到调用函数的函数名和注释
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__)#打印出调用函数的函数名 print(holiday.__doc__)#打印出调用函数的函数的注释 #结果: #holiday #这是一个放假通知
# 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__)#打印出调用函数的函数名 print(holiday.__doc__)#打印出调用函数的函数的注释 #把第一行和第三行代码去掉,结果 #inner #None
2、带参数的装饰器
如果在一段时间内需要用到装饰器函数,但过这段时间又不用的时候,就可以用带参数的装饰器
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()
3、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())