本文实例讲述了Python装饰器用法。分享给大家供大家参考，具体如下：

用类作为装饰器

示例一

最初代码：

class bol(object):

def __init__(self, func):

self.func = func

def __call__(self):

return "{}".format(self.func())

class ita(object):

def __init__(self, func):

self.func = func

def __call__(self):

return "{}".format(self.func())

@bol

@ita

def sayhi():

return 'hi'

改进一：

class sty(object):

def __init__(self, tag):

self.tag = tag

def __call__(self, f):

def wraper():

return "{res}{tag}>".format(res=f(), tag=self.tag)

return wraper

@sty('b')

@sty('i')

def sayhi():

return 'hi'

改进二：

class sty(object):

def __init__(self, *tags):

self.tags = tags

def __call__(self, f):

def wraper():

n = len(self.tags)

return "{0}{1}{2}".format((''*n).format(*self.tags), f(), ('{}>'*n).format(*reversed(self.tags)))

return wraper

@sty('b', 'i')

def sayhi():

return 'hi'

print(sayhi())

改进三：

class sty(object):

def __init__(self, *tags):

self.tags = tags

def __call__(self, f):

def wraper(*args, **kwargs):

n = len(self.tags)

return "{0}{1}{2}".format((''*n).format(*self.tags), f(*args, **kwargs), ('{}>'*n).format(*reversed(self.tags)))

return wraper

@sty('b', 'i')

def say(word='Hi'):

return word

print(say())

print(say('Hello'))

示例二

最初代码：

import threading

import time

class DecoratorClass(object):

def __init__(self):

self.thread = None

def __call__(self, func, *args, **kwargs):

def wrapped_func(*args, **kwargs):

curr_thread = threading.currentThread().getName()

self.thread = curr_thread

print('\nthread name before running func:', self.thread)

ret_val = func()

print('\nthread name after running func:', self.thread)

return ret_val

return wrapped_func

@DecoratorClass()

def decorated_with_class():

print('running decorated w class')

time.sleep(1)

return

threads = []

for i in range(5):

t = threading.Thread(target=decorated_with_class)

threads.append(t)

t.setDaemon(True) # 守护

t.start()

改进：进程锁

import threading

import time

class DecoratorClass(object):

def __init__(self):

self.thread = None

self.lock = threading.Lock()

def __call__(self, func, *args, **kwargs):

def wrapped_func(*args, **kwargs):

self.lock.acquire()

curr_thread = threading.currentThread().getName()

self.thread = curr_thread

print('thread name before running func:', self.thread)

ret_val = func()

print('\nthread name after running func:', self.thread)

self.lock.release()

return ret_val

return wrapped_func

@DecoratorClass()

def decorated_with_class():

print('Let me sleep 1 second...')

time.sleep(1)

return

threads = []

for i in range(5):

t = threading.Thread(target=decorated_with_class)

threads.append(t)

t.start()

希望本文所述对大家Python程序设计有所帮助。