import time
def dec(fun):
  start = time.time()
  fun()
  end = time.time()
  a = end - start
  print a
def myfun():
  print 'run myfunction'
dec(myfun)

運(yùn)行結(jié)果

(virt2) root@ubuntu:/home/z# python z.py
run myfunction
0.00108599662781

但是每次運(yùn)行myfun都要調(diào)用dec，下面作下變動(dòng)解決這個(gè)問(wèn)題

2.

import time
def dec(fun):
  def wrap():
    start = time.time()
    fun()
    end = time.time()
    a = end - start
    print a
  return wrap
def myfun():
  print 'run myfunction'
myfun=dec(myfun)
myfun()

運(yùn)行結(jié)果：

(virt2) root@ubuntu:/home/z# python z.py
run myfunction
0.00122618675232

這個(gè)裝飾器dec就實(shí)現(xiàn)了，并且不影響函數(shù)myfun功能

3. 裝飾器@符

import time
def dec(fun):
  def wrap():
    start = time.time()
    fun()
    end = time.time()
    a = end - start
    print a
  return wrap
@dec
def myfun():
  print 'run myfunction'
myfun()

結(jié)果

(virt2) root@ubuntu:/home/z# python z.py
run myfunction
0.000470876693726

使用了@后，就不用給myfun重新賦值了

@dec就相當(dāng)于myfun=dec(myfun)

例子：

def level(leveel):
  def debug(func):
    def wrapper(*args, **kwargs):
      print("[DEBUG]: enter {}()".format(func.__name__),leveel)
      return func(*args, **kwargs)
    return wrapper
  return debug
@level(leveel='debuging')
def say(something):
  print ("hello {}!".format(something))
say(123)

輸出：

('[DEBUG]: enter say()', 'debuging')
hello 123!

'''
class logging(object):
  def __init__(self, func):
    self.func = func
  def __call__(self, *args, **kwargs):
    print ("[DEBUG]: enter function {func}()".format(
      func=self.func.__name__))
    return self.func(*args, **kwargs)
@logging
def say(something):
  print ("say {}!".format(something))
'''
class logging(object):
  def __init__(self, level='INFO'):
    self.level = level
  def __call__(self, func): # 接受函數(shù)
    def wrapper(*args, **kwargs):
      print ("[{level}]: enter function {func}()".format(
        level=self.level,
        func=func.__name__))
      func(*args, **kwargs)
    return wrapper #返回函數(shù)
@logging(level='INFO')
def say(something):
  print ("say {}!".format(something))
say(123)

輸出：