多线程

多线程

1、简单例子：

import threading
import time

def work(n):
    time.sleep(2)
    print ("threading :",n)

time1 = time.time()

t1 = threading.Thread(target=work,args=("alex",))
t2 = threading.Thread(target=work,args = ("kaka",))
t1.start()
t2.start()
time2 = time.time()
print (time2 - time1)

2、用类实现：

class MyThread(threading.Thread):
    def __init__(self,n):
        super(MyThread, self).__init__()
        self.n = n
    def run(self):
        print ("run",self.n)

a = MyThread("kaka")
b = MyThread("wawa")

a.run()
b.run()
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3、主线程启动子线程，子线程独立运行（由原串行变为并行）；

import threading
import time

def work(n):
    time.sleep(2)
    print ("threading :",n)
start_time = time.time()
for i in range(50):
    t = threading.Thread(target=work,args = ("threading %s" % i,))
    t.start()
cost = time.time()-start_time
print ("耗时%s" % cost)

4、join()

import threading
import time

def work(n):
    print ("threading %s is start!" % n)
    time.sleep(2)
    print ("threading %s is done!:" % n)
start_time = time.time()
res_list = []
for i in range(50):
    t = threading.Thread(target=work,args = ("threading %s" % i,))
    t.start()
    res_list.append(t)
for t in res_list:#join相当于wait的意思；等待所有线程结束后，再往下走;
    t.join()
cost = time.time()-start_time
print ("耗时%s" % cost)

5、

多线程

原文：http://www.cnblogs.com/wulafuer/p/7896100.html