python开发之thread线程基础实例入门-Python Tutorial-php.cn

本文实例讲述了python开发之thread线程基础。分享给大家供大家参考，具体如下：

说到线程，我们要知道啥是串行，啥是并行程序

举个例子：

串行程序，就是一个一个的执行程序

#python threading
import time
'''
  每一秒中，输出：this is a demo!
'''
def serial():
  '''串行输出'''
  time.sleep(1)
  print('this is a demo!')
def main():
  for i in range(5):
    serial()
if __name__ == '__main__':
  main()

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运行结果如下：

>>> 
this is a demo!
this is a demo!
this is a demo!
this is a demo!
this is a demo!
>>>

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并行程序，就是很多个程序在同一时间(宏观)一起执行

#python threading
import threading
import time
'''
  并行执行，输出：Good!Good!Good!Good!Good!
'''
def parallel():
  '''并行输出'''
  time.sleep(1)
  print('Good!')
def main():
  for i in range(5):
    t = threading.Thread(target=parallel)
    t.start()
if __name__ == '__main__':
  main()

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当然我们通过执行程序，可以知道，并行程序要比串行程序执行的要快....

我们也可以获取到当前的线程及个数：

#python threading
import threading
import time
'''
  并行执行，输出：
  [<Thread(Thread-2, started 3480)>, <Thread(Thread-1, started 660)>,
  <Thread(SockThread, started daemon 2920)>, <Thread(Thread-3, started 916)>,
  <Thread(Thread-4, started 3476)>, <_MainThread(MainThread, started 3964)>,
  <Thread(Thread-5, started 2060)>]
  存在的线程数 ： 7
  Good!Good!Good!Good!Good!
'''
def parallel():
  '''并行输出'''
  time.sleep(1)
  print('Good!')
def main():
  for i in range(5):
    t = threading.Thread(target=parallel)
    t.start()
if __name__ == '__main__':
  main()
  print(threading.enumerate())
  print('存在的线程数 ： %d'%threading.active_count())

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运行结果如下：

>>> 
[<Thread(SockThread, started daemon 15424)>, <Thread(Thread-3, started 15840)>, <Thread(Thread-1, started 10884)>, <Thread(Thread-2, started 14512)>, <Thread(Thread-4, started 13204)>, <_MainThread(MainThread, started 12924)>, <Thread(Thread-5, started 15476)>]
存在的线程数 ： 7
>>> Good!Good!Good!Good!Good!

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希望本文所述对大家Python程序设计有所帮助。

Related labels：

python thread

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