多任务

import threading
from time import sleep,ctime
def sing():
    for i in range(3):
        print(11111)
        sleep(1)
def dance():
    for i in range(5):
        print(222)
if __name__ ==‘__main__‘:
    t1 = threading.Thread(target=sing)
    t2 = threading.Thread(target=dance)
    t1.start()
    t2.start()

import threading
from time import sleep,ctime
def sing():
    for i in range(3):
        print(11111)
        sleep(1)
def dance():
    for i in range(5):
        print(222)
if __name__ ==‘__main__‘:
    t1 = threading.Thread(target=sing)
    t2 = threading.Thread(target=dance)
    t1.start()
    t2.start()
    while True:
        length = len(threading.enumerate())
        print(‘当前的进程数：%d‘%length)
        if length<=1:
            break
        sleep(0.5)

 threading import Thread
import time

g_num = 100

def work1():
    global g_num
    for i in range(3):
        g_num += 1

    print("----in work1, g_num is %d---"%g_num)


def work2():
    global g_num
    print("----in work2, g_num is %d---"%g_num)


print("---线程创建之前g_num is %d---"%g_num)

t1 = Thread(target=work1)
t1.start()

#延时一会，保证t1线程中的事情做完
time.sleep(1)

t2 = Thread(target=work2)
t2.start()

import threading
import time
g_num = 0
def test1():

    global g_num
    for i in range(100000000):
        mutex.acquire()
        g_num+=1
        mutex.release()
    print(‘test1___%d‘%g_num)
def test2():
    global g_num
    for i in range(100):
        g_num+=1
    print(‘test2___%d‘%g_num)
mutex = threading.Lock
p1 = threading.Thread(target=test1,)
p1.start()

p2= threading.Thread(target=test2,)
p2.start()