线程
线程开启的两种方式
1
from threading import Thread
import time
def test():
print('hello world')
t=Thread(target=test)
t.start()
print('hello')
time.sleep(1)
print('world')
2
from threading import Thread
import time
class mythread(Thread):
def run(self):
print('hello world')
time.sleep(1)
print('hhh')
m=mythread()
m.start()
print('ok')
子线程和子进程的创建速度
from threading import Thread
from multiprocessing import Process
import time
def test(name):
print('hello world',name)
time.sleep(1)
print('ok',name)
if __name__ == '__main__':
p=Process(target=test,args=('子进程',))
t=Thread(target=test,args=('子线程',))
print('zhu')
p.start()
t.start()
print('zhu1')
子线程共享资源
from threading import Thread
import os,time
x=100
def test():
global x
x=50
print('hello ',x)
print(os.getpid())
t=Thread(target=test)
t.start()
print('zhu ',x)
print(os.getpid())
线程的join方法
from multiprocessing import Process
from threading import Thread
import time
def task():
print('进程 开启')
time.sleep(10)
print('进程 结束')
def task2():
print('子线程 开启')
time.sleep(2)
print('子线程 结束')
if __name__ == '__main__':
p = Process(target=task)
t = Thread(target=task2)
t.start() # 开线程
p.start() # 开进程
print('子进程join开始')
p.join() # 主进程的主线程等待子进程运行结束
print('主')
守护线程
from threading import Thread
import time
def shouhu():
print('我是守护xian程')
time.sleep(10)
print('shouhu end')
t=Thread(target=shouhu)
t.daemon=True
t.start()
print('nice')
线程其他用法
from threading import Thread,currentThread,enumerate,activeCount
# import threading
import time
# threading.current_thread()
# threading.current_thread()
def task():
print('子线程 start')
time.sleep(2)
print('子线程 end')
print(enumerate())
# print(currentThread(),'子线程')
if __name__ == '__main__':
t1 = Thread(target=task)
t2 = Thread(target=task)
t1.start()
t2.start()
print(t1.is_alive()) # True
print(t1.getName()) # Thread-1
print(t2.getName()) # Thread-2
t1.setName('班长')
print(t1.getName())
print(currentThread().name)
print(enumerate()) # [<_MainThread(MainThread, started 1856)>, <Thread(Thread-1, started 6948)>, <Thread(Thread-2, started 3128)>]
print(activeCount()) # 3
print(len(enumerate())) # 3
