def __enter__(self):
    return self._lock.__enter__()
  def __exit__(self, *args):
    return self._lock.__exit__(*args)

import threading
from threading import Condition
# condition
class XiaoAi(threading.Thread):
  def __init__(self, cond):
    self.cond = cond
    super().__init__(name="xiaoai")
  def run(self):
    self.cond.acquire()
    self.cond.wait()
    print('{}:ennn. '.format(self.name))
    self.cond.notify()
    self.cond.wait()
    print('{}:好嗒. '.format(self.name))
    self.cond.release()
class TianMao(threading.Thread):
  def __init__(self, cond):
    super().__init__(name="tiaomao")
    self.cond = cond
  def run(self):
    self.cond.acquire()
    print('{}:hello ~ xiaoai. '.format(self.name))
    self.cond.notify()
    self.cond.wait()
    print('{}:我们来念一首诗吧! . '.format(self.name))
    self.cond.notify()
    self.cond.release()
if __name__ == '__main__':
  condition = Condition()
  xiaoai = XiaoAi(condition)
  tianmao = TianMao(condition)
  # 启动顺序很重要
  xiaoai.start()
  tianmao.start()