python thread

from threading import Thread
t = Thread(target,args)
target：表示调用对象，即线程要执行的任务
args：表示调用对象的参数”元组“

t.start()  #启动线程

t.join()   #等待线程执行结束在执行后面的代码

from threading import Thread
import time

def func():
    print(‘子进程‘)

if __name__ == ‘__main__‘:
    t = Thread(target=func)
    t.start()
    time.sleep(1)
    print(‘主进程‘)

from threading import Thread
from multiprocessing import Process
import os
import time
def son(n):
    pass

if __name__ == ‘__main__‘:
    start = time.time()
    for i in range(100):
        t = Thread(target=son,args=(‘线程‘,))
        t.start()
    print(time.time() - start)
    
    for i in range(100):
        p = Process(target=son,args=(‘进程‘,))
        p.start()
    print(time.time() - start)

from threading import Lock,RLock

Lock() #互斥锁,一把钥匙配一把锁
l = Lock()  #创建锁
l.acquire()  #上锁
l.acquire()  #死锁
print(123)
l.release()   #开锁
l.release()

RLock() #递归锁,可以有无止尽的锁,但是会有一把万能钥匙,同一进程下不会阻塞，不同进程会阻塞
l = RLock()  #创建锁
l.acquire()    #上锁
l.acquire()    #上锁，同一进程下不会死锁
print(123)   
l.release()    #开锁
l.release()    #开锁，上多少锁就开多少锁