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python开发之thread线程基础实例入门

运维开发网 https://www.qedev.com 2020-03-11 12:11 出处:网络 作者: Hongten
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:

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()

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!
>>>

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()

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())

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!

希望本文所述对大家Python程序设计有所帮助。

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