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Python裝飾器用法實(shí)例分析

更新時(shí)間：2019年01月14日 09:46:11 作者：貝貝愛豆豆

這篇文章主要介紹了Python裝飾器用法,結(jié)合實(shí)例形式分析了帶參數(shù)裝飾器、無參數(shù)裝飾器等相關(guān)實(shí)現(xiàn)與使用技巧,需要的朋友可以參考下

本文實(shí)例講述了Python裝飾器用法。分享給大家供大家參考，具體如下：

無參數(shù)的裝飾器

#coding=utf-8
def log(func):
  def wrapper():
    print 'before calling ',func.__name__
    func()
    print 'end calling ',func.__name__
  return wrapper
@log
def hello():
  print 'hello'
@log
def hello2(name):
  print 'hello',name
if __name__=='__main__':
  hello()

運(yùn)行結(jié)果：

before calling hello
hello
end calling hello

帶參數(shù)的裝飾器:

#coding=utf-8
def log(func):
  def wrapper(name):
    print 'before calling ',func.__name__
    func(name)
    print 'end calling ',func.__name__
  return wrapper
@log
def hello(name):
  print 'hello',name
@log
def hello2(name):
  print 'hello',name
if __name__=='__main__':
  hello('haha')

運(yùn)行結(jié)果：

before calling hello
hello haha
end calling hello

多個(gè)參數(shù)的時(shí)候:

#coding=utf-8
def log(func):
  '''
  *無名字的參數(shù)
  **有名字的參數(shù)
  :param func:
  :return:
  '''
  def wrapper(*args,**kvargs):
    print 'before calling ',func.__name__
    print 'args',args,'kvargs',kvargs
    func(*args,**kvargs)
    print 'end calling ',func.__name__
  return wrapper
@log
def hello(name,age):
  print 'hello',name,age
@log
def hello2(name):
  print 'hello',name
if __name__=='__main__':
  hello('haha',2)
  hello(name='hehe',age=3)

輸出:

end calling hello
before calling hello
args () kvargs {'age': 3, 'name': 'hehe'}
hello hehe 3
end calling hello

裝飾器里帶參數(shù)的情況

本質(zhì)就是嵌套函數(shù)

#coding=utf-8
def log(level,*args,**kvargs):
  def inner(func):
    def wrapper(*args,**kvargs):
      print level,'before calling ',func.__name__
      print level,'args',args,'kvargs',kvargs
      func(*args,**kvargs)
      print level,'end calling ',func.__name__
    return wrapper
  return inner
@log(level='INFO')
def hello(name,age):
  print 'hello',name,age
@log
def hello2(name):
  print 'hello',name
if __name__=='__main__':
  hello('haha',2)

運(yùn)行輸出：