#扫描给定网络中存活的主机(通过ping来测试,有响应则说明主机存活)
import sys
import subprocess
import time
def ping(net,start=100,end=200,n=2,w=5):
    for i in range(start,end+1):
        ip=net+"."+str(i)
        command="ping %s -n %d -w %d"%(ip,n,w)
        print(ip,("通","不通")[subprocess.call(command,stdout=open("nul","w"))]) #stdout=open("nul","w") #不显示命令执行返回的结果
t1=time.time()
if len(sys.argv)!=2:
    print("参数输入错误!")
    print("运行示例:")
    print("test01.py 123.125.114")
elif len(sys.argv)==2:
    net=sys.argv[1]
    ping(net)
t2=time.time()
print("程序耗时%f秒!"%(t2-t1))   #195.091611秒

import sys
import subprocess
import time
from threading import Thread
#在python里面，线程的创建有两种方式，其一使用Thread类创建
# 导入Python标准库中的Thread模块 
#from threading import Thread #
# 创建一个线程 
#mthread = threading.Thread(target=function_name, args=(function_parameter1, function_parameterN)) 
# 启动刚刚创建的线程 
#mthread .start()
#function_name: 需要线程去执行的方法名
#args: 线程执行方法接收的参数，该属性是一个元组，如果只有一个参数也需要在末尾加逗号。

result=[]
def ping1(ip):
    command="ping %s -n 1 -w 20"%(ip)
    result.append([ip,subprocess.call(command)])
def ping(net,start=100,end=200):
    for i in range(start,end+1):
        ip=net+"."+str(i)
        th=Thread(target=ping1,args=(ip,))
        th.start()
    
def main():
    if len(sys.argv)!=2:
        print("参数输入错误!")
        print("运行示例:")
        print("test01.py 123.125.114")
    elif len(sys.argv)==2:
        net=sys.argv[1]
        ping(net)
if __name__=='__main__':
    t1=time.time()
    main()
    while len(result)!=101:
        time.sleep(1)
print(result)        
t2=time.time()
print("程序耗时%f秒!"%(t2-t1))   #1.585263秒

多线程
#爬取股票的价格
import requests
import re
import time
from threading import Thread

code=[600016,600000,601939,600036,603683,600050,601890,600795,601857,600584,601231,603165,600644,603005,601198,603690,600643,600131,600776,603609,601377]
m1=re.compile(r"price: '(\d{1,3}\.\d{2}')")
def getprice(id):
    url="http://quotes.money.163.com/0%s.html"%id
    txt=requests.get(url).text
    price=m1.search(txt).group(1)
    print(id,price)

if __name__=="__main__":
    ts=[]
    start=time.time()
    for id in code:
        t=Thread(target=getprice,args=(id,))
        ts.append(t)
        t.start()
    for t in ts:
        t.join()    #等待子线程运行完，主线程再运行
    print("程序耗时:",time.time()-start)     

#多进程
#爬取股票的价格
import requests
import re
import time
from multiprocessing import Process
from threading import Thread 
code=[600016,600000,601939,600036,603683,600050,601890,600795,601857,600584,601231,603165,600644,603005,601198,603690,600643,600131,600776,603609,601377]
m1=re.compile(r"price: '(\d{1,3}\.\d{2}')") 
def getprice(id):
    url="http://quotes.money.163.com/0%s.html"%id
    txt=requests.get(url).text
    price=m1.search(txt).group(1)
    print(id,price)
ps=[]   #进程池    
if __name__=="__main__":
    start=time.time()
    for id in code:
        p=Process(target=getprice,args=(id,))
        ps.append(p) #把进程放入列表(进程池)
        p.start()   #启动进程
    for p in ps:
        p.join()
    print(time.time()-start)  

#爬取股票的价格
import requests
import re
import time
from multiprocessing import Pool
#多进程带Pool
 
code=[600016,600000,601939,600036,603683,600050,601890,600795,601857,600584,601231,603165,600644,603005,601198,603690,600643,600131,600776,603609,601377]
m1=re.compile(r"price: '(\d{1,3}\.\d{2}')")     
def getprice(id):
    url="http://quotes.money.163.com/0%s.html"%id
    txt=requests.get(url).text
    price=m1.search(txt).group(1)
    print(id,price)

if __name__=="__main__":
    start=time.time()
    p=Pool(4)
    for id in code:
        p.apply_async(getprice,args=(id,))  #async异步，第一个参数是函数名，第二个是此函数的参数
    p.close()   
    p.join()    #等待子线程运行完，主线程再运行
    print("程序耗时:",time.time()-start)