多线程实例

import threading
import time

def fun(n):
    print("task",n)
    time.sleep(2)
    print("task done",n)

start_time = time.time()
t_objs = []

for i in range(50):
    t = threading.Thread(target=fun,args=("task_%s"%i,))
    t.start()
    t_objs.append(t)
for t in t_objs:
    t.join()
print("all task has done")

print("cost",time.time() - start_time)

1，实现了多线程的并发，主进程在等待各个线程执行结束之后才继续往下执行

2 ，t.join(）让进程等待当前线程结束。

3 ，线程的实例

 》》》》》》》》》》》》》线程2

import threading
import time

class MyThread(threading.Thread):
    def __init__(self,n,sleep_time):
        super (MyThread,self).__init__()
        self.n = n
        self.sleep_time = sleep_time

    def run(self):
        print("run task",self.n)
        time.sleep(self.sleep_time)
        print("task has done",self.n)

t1 = MyThread("t1",2)
t2 = MyThread("t2",4)

t1.start()
t2.start()

t1.join()

print("main process")

1，类的方式定义多线程并发

 

》》》》》》》》线程3

 

import threading,time

def run(n):
    print("task ",n)
    time.sleep(2)
    print("task has done",n,threading.current_thread())#打印当前进程

start_time = time.time()#主进程开始时间
t_objs = []#存线程实例

for i in range(50):
    t = threading.Thread(target=run,args=("task %s"%i,))
    t.setDaemon(True)#把当前线程设置为守护线程
    t.start()
    t_objs.append(t)

for t in t_objs:
    t.join()

print("all threads has done",threading.active_count(),threading.current_thread())
print("cost",time.time()-start_time)

1，t.setDaemon(True)#把当前线程设置为守护线程

2，threading.active_count() 活跃的线程

     threading.current_thread() 当前执行的线程

 

三》》》多进程

import multiprocessing,time,threading

def fun():
    print("线程开始")
    print(threading.get_ident())
    print("线程结束")

def run(name):
    time.sleep(2)
    print("hellow world",name)
    t = threading.Thread(target=fun,)
    t.start()

if __name__ == '__main__':
    for i in range(5):
        p = multiprocessing.Process(target=run, args=("bob%s"%i,))
        p.start()
    # p = multiprocessing.Process(target = run,args=("bob",))
    # p.start()
    # p.join()

　1.启动5个进程，每个进程中启动一个线程

》》》》GET 进程id

from multiprocessing import Process
import os

def info(title):
    print(title)
    print("moudle name",__name__)
    print("parent process",os.getppid())
    print("process id",os.getpid())
    print("\n\n")

def f(name):
    info("called from child process function")
    print("hellow ",name)

if __name__=='__main__':
    info("main process line")
    p = Process(target=f,args=("cero",))
    p.start()
    p.join()

　　》》》》