多线程-threading
python的thread模块是比较底层的模块，python的threading模块是对thread做了一些包装的，可以更加方便的被使用
1. 使用threading模块
单线程执行
#coding=utf-8
import time
def saySorry():
print("亲爱的，我错了，我能吃饭了吗？")
time.sleep(1)
if __name__ == "__main__":
for i in range(5):
saySorry()
多线程执行
#coding=utf-8
import threading
import time
def saySorry():
print("亲爱的，我错了，我能吃饭了吗？")
time.sleep(1)
if __name__ == "__main__":
for i in range(5):
t = threading.Thread(target=saySorry)
t.start() #启动线程，即让线程开始执行
2. 主线程会等待所有的子线程结束后才结束
#coding=utf-8
import threading
from time import sleep,ctime
def sing():
for i in range(3):
print("正在唱歌...%d"%i)
sleep(1)
def dance():
for i in range(3):
print("正在跳舞...%d"%i)
sleep(1)
if __name__ == '__main__':
print('---开始---:%s'%ctime())
t1 = threading.Thread(target=sing)
t2 = threading.Thread(target=dance)
t1.start()
t2.start()
#sleep(5) # 屏蔽此行代码，试试看，程序是否会立马结束？
print('---结束---:%s'%ctime())
3. 查看线程数量
#coding=utf-8
import threading
from time import sleep,ctime
def sing():
for i in range(3):
print("正在唱歌...%d"%i)
sleep(1)
def dance():
for i in range(3):
print("正在跳舞...%d"%i)
sleep(1)
if __name__ == '__main__':
print('---开始---:%s'%ctime())
t1 = threading.Thread(target=sing)
t2 = threading.Thread(target=dance)
t1.start()
t2.start()
while True:
length = len(threading.enumerate())
print('当前运行的线程数为：%d'%length)
if length<=1:
break
sleep(0.5)
