python 多线程

例一：不使用多线程

#-*-coding:utf-8-*-
#compare for multi threadsafety
import time

def worker():
    print "worker"
    time.sleep(1)
    return
if __name__=="__main__":
    for i in xrange(5):
        worker()

例二：使用多线程

#-*-coding:utf-8-*-
import threading
import time
 
def worker():
    print "worker"
    time.sleep(1)
    return
 
for i in xrange(5):
    t=threading.Thread(target=worker)
    t.start()

例三：返回线程和主线程

#-*-coding:utf-8-*-
import threading
import time
 
def worker():
    print "worker"
    time.sleep(1)
    return
 
for i in xrange(5):
    t=threading.Thread(target=worker)
    t.start()
print "current has %d threads" % (threading.activeCount() - 1)

例四：threading.enumerate()的使用。此方法返回当前运行中的Thread对象列表

#!/usr/bin/python
#test the variable threading.enumerate()
import threading
import time
 
def worker():
    print "test"
    time.sleep(2)
 
threads = []
for i in xrange(5):
    t = threading.Thread(target=worker)
    threads.append(t)
    t.start()
 
for item in threading.enumerate():
    print item
 
print
 
for item in threads:
    print item

例五：threading.setDaemon()的使用。设置后台进程。