python开发之thread线程基础实例入门
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。
