用类作为装饰器

练习一

最初代码

class bol(object):

  def __init__(self, func):

    self.func = func

  def __call__(self):

    return "<b>{}</b>".format(self.func())

class ita(object):

  def __init__(self, func):

    self.func = func

  def __call__(self):

    return "<i>{}</i>".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 "<{tag}>{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'))

练习二

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()