python网络编程学习笔记（一）

来源：互联网发布：淘宝无踪之岛的馈赠编辑：程序博客网时间：2024/05/17 07:42

python网络编程学习笔记（一）

python网络编程基础，第四版
pycharm实现，python版本2.7.5

第一部分底层网络

一、笔记

#coding=utf-8第一章import socket,sysport=70print (len(sys.argv))for i in range(len(sys.argv)):    print (sys.argv[i])host=sys.argv[1]filename=sys.argv[2]s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)print ("old s is:",s)print (host)s.connect((host,port))print ("new s is:",s)s.sendall(filename+"\r\n")while 1:    buf=s.recv(2048)    if not len(buf):        break    sys.stdout.write(buf)

加入错误处理

import socket,sysport=70print (len(sys.argv))for i in range(len(sys.argv)):    print (sys.argv[i])host=sys.argv[1]filename=sys.argv[2]s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)print ("old s is:",s)print (host)try:  s.connect((host, port))except socket.gaierror,e:    print ("ERROR connection to server:%s" %e)    sys.exit(1)s.sendall(filename+"\r\n")while 1:    buf=s.recv(2048)    if not len(buf):        break    sys.stdout.write(buf)文件接口类重写import socket,sysport=70host=sys.argv[1]filename=sys.argv[2]s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.connect((host,port))fd=s.makefile('rw',0)fd.write(filename+"\r\n")for line in fd.readlines():    sys.stdout.write(line)

基本服务器操作

import sockethost=''port=80s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.bind((host,port))s.listen(1)print "Server is running on port %d;press ctrl-c to\    terminate."% portwhile 1:    clientsock,clientaddr=s.accept()    clientfile=clientsock.makefile('rw',0)    clientfile.write("welcome,"+str(clientaddr)+"/n")    clientfile.write("Please enter a string:")    line=clientfile.readline().strip()    clientfile.write("You entered %d characters.\n"%len(line))    clientfile.close()    clientsock.close()

高级接口

import gopherlib,syshost=sys.argv[1]file=sys.argv[2]f=gopherlib.send_selector(file,host)for line in f.readlines():    sys.stdout.write(line)import urllib,syshost=sys.argv[1]file=sys.argv[2]f=urllib.urlopen('gopher://%s%s'%(host,file))for line in f.readlines():    sys.stdout.write(line)import urllib,sysf=urllib.urlopen(sys.argv[1])while 1:    buf=f.read(2048)    if not len(buf):        break    sys.stdout.write(buf)

第二章
使用udp

第三章网络服务器

import socketsolist=[x for x in dir(socket) if x.startswith('SO')]solist.sort()for x in solist:    print x

第四章域名系统

import sys,socketresult=socket.getaddrinfo(sys.argv[1],None)print result[0][4]import sys,socketresult=socket.getaddrinfo(sys.argv[1],None)counter=0for item in result:    print "%-2d:%s"%(counter,item[4])    counter+=1P70import sys,socketresult=socket.getaddrinfo(sys.argv[1],None,0,socket.SOCK_STREAM)counter=0for item in result:    print "%-2d:%s"%(counter,item[4])    counter+=1

执行反向查询

import sys,sockettry:    result=socket.gethostbyaddr(sys.argv[1])    print "Primary hostname:"    print " "+result[0]    print "\nAddresses:"    for item in result[2]:        print " "+itemexcept socket.herror,e:    print "Couldn't look up name:",e

正反向查询

import sys,socketdef getipaddrs(hostname):     result=socket.getaddrinfo(hostname,None,0,socket.SOCK_STREAM)     return [x[4][0] for x in result]def gethostname(ipaddr):    return socket.gethostbyaddr(ipaddr)[0]try:    hostname=gethostname(sys.argv[1])    ipaddrs=getipaddrs(hostname)except socket.herror,e:    print "NO host names available for %s;it may be normal"%sys.argv[1]    sys.exit(0)except socket.gaierror,e:    print "Got hostname %s,but it could not be forward-resolved:%s"%(hostname,str(e))    sys.exit(1)if not sys.argv[1] in ipaddrs:    print "GOt hostnae %s,but no forward lookup,"% hostname    print "original IP %s did not appear in IP address list"% sys.argv[1]    sys.exit(1)print "Validated hostname:",hostname

获得完整域名，gethostname()获得主机名，getfqdn()获得完整信息，getaddrinfo()获得该域名对性的IP地址。

import sys,socketdef getipaddrs(hostname):    result=socket.getaddrinfo(hostname,None,0,socket.SOCK_STREAM)    return [x[4][0] for x in result]hostname=socket.gethostname()print "Host name:",hostnameprint "Fully-qualified name:",socket.getfqdn(hostname)try:    print "IP addresses:",",".join(getipaddrs(hostname))except socket.gaierror,e:    print "Couldn't not get IP addresses:",eimport sys,DNSquery=sys.argv[1]DNS.DiscoverNameServers()reqobj=DNS.Request()answerobj=reqobj.req(name=query,qtrpe=DNS.Type.ANY)if not len(answerobj.answers):    print "NOT found."for item in answerobj.answers:    print "%-5s %s"%(item['typename'],item['data'])import sys,DNSdef hierquery(qstring,qtype):#给出主机名的相应服务器    reqobj=DNS.Request()#建立查询对象实例    try:        answerobj=reqobj.req(name=qstring,qtype=qtype)        answers=[x['data'] for x in answerobj.answers if x['type']==qtype]    except DNS.Base.DNSError:        answers=[]    if len(answers):        return answers    else:        remainder=qstring.split(".",1)        if len(remainder)==1:            return None        else:            return hierquery(remainder[1],qtype)def findnameservers(hostname):#取得权威名称服务器列表    return hierquery(hostname,DNS.Type.NS)def getrecordsfromnameserver(qstring,qtype,nslist):#在服务器查询，直到找到答案或者查完该表    for ns in nslist:        reqobj=DNS.Request(server=ns)        try:            answers=reqobj.req(name=qstring,qtype=qtype).answers            if len(answers):                return answers        except DNS.Base.DNSError:            pass        return []def nslookup(qstring,qtype,verbose=1):    nslist=findnameservers(qstring)    if nslist==None:        raise RuntimeError,"Could not find nameserver to use."    if verbose:        print "using nameserver:",",".join(nslist)    return getrecordsfromnameserver(qstring,qtype,nslist)if __name__=='__main__':    query=sys.argv[1]    DNS.DiscoverNameServers()    answers=nslookup(query,DNS.Type.ANY)    if not len(answers):        print "not found."    for item in answers:        print "%-5s %s"%(item['typename'],item['data'])

第五章
超时的用法
echoserver.py

import socket,tracebackhost = ''port = 51432s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.bind((host,port))s.listen(1)while True:    try:        clientsock,clientaddr = s.accept()    except KeyboardInterrupt:        raise    except:        traceback.print_exc()        continue    try:        print "Got connection from",clientsock.getpeername()        while  True:            data = clientsock.recv(4096)            if not len(data):                break            clientsock.sendall(data)    except (KeyboardInterrupt,SystemExit):        raise    except:        traceback.print_exc()    try:        clientsock.close()    except KeyboardInterrupt:        raise    except:        traceback.print_exc()import struct,sysdef htones(num):    return struct.pack('!H',num)def htonl(num):    return struct.pack('!I',num)def ntohs(data):    return struct.unoack('!H',data)[0]def ntohl(data):    return struct.unpack('!I',data)[0]def sendstring(data):    return htonl(len(data))+dataprint "Enter a string:"str=sys.stdin.readline().rstrip()print repr(sendstring(str))import socket,syshost,port = sys.argv[1:]results = socket.getaddrinfo(host,port,0,socket.SOCK_STREAM)for result in results:    print "-"*60    if result[0] == socket.AF_INET:        print "Family: AF_INET"    elif result[0] == socket.AF_INET6:        print "Family: AF_INET6"    else:        print "Family:",result[0]    if result[1] == socket.SOCK_STREAM:        print "Socket Type: SOCK_STREAM"    elif result[1] == socket.SOCK_DGRAM:        print "Socket Type: SOCK_DGRAM"    print "Protocol:",result[2]    print "Canonical Name:",result[3]    print "Socket Address:",result[4]

先找ipv4,再找ivp6
Connect Example with ipv6 Awareness ------------- ipv6connect.py

import socket,sysdef getaddrinfo_pref(host,port,socktype,familypreference=socket.AF_INET):#ipv4    results = socket.getaddrinfo(host,port,0,socktype)    for result in results:        if result[0] == familypreference:            return result    return results[0]host = sys.argv[1]port = 'http'c = getaddrinfo_pref(host,port,socket.SOCK_STREAM)print "Connecting to",c[4]s = socket.socket(c[0],c[1])s.connect(c[4])s.sendall("HEAD / HTTP/1.0\n\n")while True:    buf = s.recv(4096)    if not len(buf):        break    sys.stdout.write(buf)Echo Server Bound to Specific Addressbindserver.pyimport socket,tracebackhost = '127.0.0.1'port = 51423s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.bind((host,port))s.listen(1)while True:    clientsock,clientaddr = s.accept()    print "Got connection from",clientsock.getpeername()    while True:        data = clientsock.recv(4096)        if not len(data):            break        clientsock.sendall(data)    clientsock.close()pull()import socket,sys,selectport = 51423host = 'localhost'spinsize = 10spinpos = 0spindir = 1def spin():    global spinsize,spinpos,spindir    spinstr = '.' * spinpos + '|' + '.'*(spinsize-spinpos-1)    sys.stdout.write('\r'+spinstr+' ')    sys.stdout.flush()    spinpos += spindir    if spinpos < 0:        spindir = 1        spinpos = 1    elif spinpos >= spinsize:        spinpos -= 2        spindir = -1s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.connect((host,port))p = select.poll()p.register(s.fileno(),select.POLLIN | select.POLLERR | select.POLLHUP)while True:    results = p.poll(50)    if len(results):        if results[0][1] == select.POLLIN:            data = s.recv(4096)            if not len(data):                print ("\rRemove end closed connection ; exiting.")                break            sys.stdout.write("\rReceived: " + data)            sys.stdout.flush()        else:            print "\rProblem occurred exitng."            sys.exit(0)    spin()selectclient.pyimport socket,sys,selectport = 51423host = 'localhost'spinsize = 10spinpos = 0spindir = 1def spin():    global spinsize,spinpos,spindir    spinstr = '.' * spinpos + '|' + '.' *(spinsize - spinpos -1)    sys.stdout.write('\r' + spinstr +' ')    sys.stdout.flush()    spinpos += spindir    if spinpos < 0:        spindir = 1        spinpos = 1    elif spinpos >= spinsize:        spinpos -= 2        spindir = -1s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.connect((host,port))while True:    infds,outfds,errfds = select.select([s],[],[s],0.05)    if len(infds):        data = s.recv(4096)        if not len(data):            print("\rRemote end closed connection; Exiting.")            break        sys.stdout.write("\rReceived: " + data)        sys.stdout.flush()    if len(errfds):        print "\rProblen occurred; exiting."        sys.exit(0)    spin()

二、TCP通信方式

服务端：

#coding=utf-8from socket import*#监听套接字的连接和回应#服务器端myHost='' #‘’代表主机所有可用端口myPort=50007sockobj=socket(AF_INET,SOCK_STREAM)#创建一个TCP scoket 对象sockobj.bind((myHost,myPort))#绑定服务端口号sockobj.listen(5)#监听，允许5个挂起连接while True:#一直监听直到进程被杀死    connection,address=sockobj.accept()#等待下个客户端连接    print('Server connected by：',address)#连接是新的scoket    while True:        data=connection.recv(1024)#读取新的客户端scoket,for 循环接收        if not data:break#发送接收报文给客户端        connection.send(b'Echo get your message:'+data)#直到结束关闭scoket，发送只能是b,bite格式    connection.close()

客户端：

#coding=utf-8import socket#客户端import sysfrom socket import *serverHost='localhost'serverPort=50007message=[b'hello network world']if len(sys.argv)>1:    serverHost=sys.argv[1]    if len(sys.argv)>2:        message=(x.encode()for x in sys.argv[2:])sockobj=socket(AF_INET,SOCK_STREAM)sockobj.connect((serverHost,serverPort))for line in message:    sockobj.send(line)    data=sockobj.recv(1024)#1024字节    print('Client received:',data)sockobj.close()

三、UDP通信方式

UDP请求端：

#coding=utf-8import socket,syshost=sys.argv[1]textpost=sys.argv[2]s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)try:    port=int(textpost)except ValueError:    print "输入错入"    port=socket.getservbyname(textpost,'udp')s.connect((host,port))print "Enter data to transmit: "data=sys.stdin.readline().strip()s.sendall(data)print "Looking for replies."while(1):    buf=s.recv(2048)    if not len(buf):        break    sys.stdout.write(buf)UDP应答端：#coding=utf-8import socket,tracebackhost=''port=54132s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.bind((host,port))while 1:    try:        message,address=s.recvfrom(8192)        print "Got data from",address        s.sendto(message,address)    except(KeyboardInterrupt,SystemExit):        raise    except:        traceback.print_exc()UDP查询时间服务端：#coding=utf-8import socket,traceback,time,structhost=''port=51432s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.bind((host,port))while 1:    try:        message,address=s.recvfrom(8192)        print message,address        secs=int(time.time())        secs-=60*60*24        secs+=220898800        reply=struct.pack("!I",secs)        s.sendto(reply,address)    except(KeyboardInterrupt,SystemExit):        raise    except:        traceback.print_exc()

客户端：

#coding=utf-8import socket,sys,struct,timehostname='localhost'port=51432host=socket.gethostbyname(hostname)s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)s.sendto('',(host,port))print "Loking for replies"buf=s.recvfrom(2048)[0]if len(buf)!=4:    print "Wrong-size reply %d:%s"%(len(buf),buf)    sys.exit(1)secs=struct.unpack("!I",buf)[0]secs-=220898800print time.ctime(int(secs))超时：#coding=utf-8import socket,tracebackhost = ''port = 51432s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.bind((host,port))s.listen(1)while True:    try:        clientsock,clientaddr = s.accept()    except KeyboardInterrupt:        raise    except:        traceback.print_exc()        continue    try:        print "Got connection from",clientsock.getpeername()        while  True:            data = clientsock.recv(4096)            if not len(data):                break            clientsock.sendall(data)    except (KeyboardInterrupt,SystemExit):        raise    except:        traceback.print_exc()    try:        clientsock.close()    except KeyboardInterrupt:        raise    except:        traceback.print_exc()四、ftp#coding=utf-8#自动抓取并打开远程文件文件import os,sysfrom getpass import getpassfrom ftplib import FTPnonpassive=Falsefilename='monkeys.jpg'dirname='.'sitename='ftp.rmi.net'userinfo=('lutz',getpass('pwd?'))if len(sys.argv)>1:filename=sys.argv[1]print('Connection...')connection=FTP(sitename)connection.login(*userinfo)connection.cwd(dirname)if nonpassive:    connection.set_pasv(False)print('Downloading...')localfile=open(filename,'wb')connection.retrbinary('RETR'+filename,localfile.write,1024)connection.quit()localfile.close()if input('Open file?') in ['Y','y']:    from PP4E.System.Media.playfile import playfile    playfile(filename)

五、广播

接收端：

#coding=utf-8import socket,tracebackhost = ''port = 51423s = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)s.setsockopt(socket.SOL_SOCKET,socket.SO_BROADCAST,1)s.bind((host,port))while True:    try:        message,address =s.recvfrom(8192)        print "Got data from ",address        s.sendto("I am here",address)    except (KeyboardInterrupt,SystemExit):        raise    except:        traceback.print_exc()

发送端：

#coding=utf-8import socket,sysdest = ('<broadcast>',51423)s = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)s.setsockopt(socket.SOL_SOCKET,socket.SO_BROADCAST,1)s.sendto("Hello",dest)print "Looking for replies; press Ctrl-C to stop."while True:    (buf,address) = s.recvfrom(2048)    if not len(buf):        break    print "Received from %s: %s" % (address,buf)

第二部分web Service

一、web客户端访问

urllib2扩展性更好
1.下载Web界面
2.在远程HTTP服务器上验证
3.提交表单（from）数据
4.处理错误
5.与非HTTP协议通信

1.下载Web界面

(1)

#coding=utf-8import sys,urllib2req=urllib2.Request(sys.argv[1])fd=urllib2.urlopen(req)while 1:    data=fd.read(1024)    if not len(data):        break    sys.stdout.write(data)

sys.stdout 是标准输出文件。write就是往这个文件写数据。
合起来就是打印数据到标准输出。类似print

运行结果：

D:\python\python.exe E:/code/python/unit6/dump_page.py
http://www.example.com

<!doctype html><html><head>    <title>Example Domain</title>    <meta charset="utf-8" />    <meta http-equiv="Content-type" content="text/html; charset=utf-8" />    <meta name="viewport" content="width=device-width, initial-scale=1" />    <style type="text/css">    body {        background-color: #f0f0f2;        margin: 0;        padding: 0;        font-family: "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;    }    div {        width: 600px;        margin: 5em auto;        padding: 50px;        background-color: #fff;        border-radius: 1em;    }    a:link, a:visited {        color: #38488f;        text-decoration: none;    }    @media (max-width: 700px) {        body {            background-color: #fff;        }        div {            width: auto;            margin: 0 auto;            border-radius: 0;            padding: 1em;        }    }    </style></head><body><div>    <h1>Example Domain</h1>    <p>This domain is established to be used for illustrative examples in documents. You may use this    domain in examples without prior coordination or asking for permission.</p>    <p><a href="http://www.iana.org/domains/example">More information...</a></p></div></body></html>

Process finished with exit code 0

(2)

#coding=utf-8import sys,urllib2req=urllib2.Request(sys.argv[1])fd=urllib2.urlopen(req)print "Retrieved",fd.geturl()info=fd.info()for key,value in info.items():    print "%s=%s"%(key,value)

运行结果如下：
D:\python\python.exe E:/code/python/unit6/dump_info.py http://httpd.apache.org/dev
Retrieved http://httpd.apache.org/dev/
content-length=8870
accept-ranges=bytes
vary=Accept-Encoding
server=Apache/2.4.7 (Ubuntu)
last-modified=Wed, 25 Jan 2017 14:38:55 GMT
connection=close
etag="22a6-546ec313cb061"
date=Fri, 17 Mar 2017 06:29:52 GMT
content-type=text/html

Process finished with exit code 0

注：从geturl()得到的值与传入Request的对象不同，结尾处多了一条斜线，远程服务器做了一个Http转向，urllib自动跟随了转向。
其他行显示Http的header信息；

2.在远程HTTP服务器上验证

(1)

#coding=utf-8import sys,urllib2,getpassclass TerminalPassword(urllib2.HTTPPasswordMgr):    def find_user_password(self, realm, authuri):        ret=urllib2.HTTPPasswordMgr.find_user_password(self,realm,authuri)        if ret[0] == None and ret[1] == None:            sys.stdout.write("Login reauired for %s at %sn" % (realm,authuri))            sys.stdout.write("Username: ")            username = sys.stdin.readline().rstrip()            password = getpass.getpass().rstrip()            return (username, password)        else:            return retreq = urllib2.Request(sys.argv[1])opener = urllib2.build_opener(urllib2.HTTPBasicAuthHandler(TerminalPassword()))response = opener.open(req)print response.read()

扩展urllib2.HTTPPasswordMgr类，允许程序在需要的时候像操作员询问用户名和密码，
build_opener：允许指定额外的处理程序，代码需要支持认证，所以HTTPBasicAuthHandler加到处理链接

3.提交表单（from）数据
GET方法：把表单数据编码至url，在给出请求的页面后，加一个问号，接着是表单的元素。每个键和值对用“&”分割，有些字符需要被避免。不适合数据量比较大的地方。

(1)

代码：#coding=utf-8import sys,urllib2req=urllib2.Request(sys.argv[1])fd=urllib2.urlopen(req)while 1:    data=fd.read(1024)    if not len(data):        break    sys.stdout.write(data)

sys.stdout 是标准输出文件。write就是往这个文件写数据。
合起来就是打印数据到标准输出。类似print

运行结果：
D:\python\python.exe E:/code/python/unit6/dump_page.py http://weixin.sogou.com/weixin?p=01030402&query=%E5%8D%9A%E5%AE%A2%E5%9B%AD&type=2&ie=utf8

<link rel="shortcut icon" href="http://logo.www.sogou.com/images/logo2014/new/favicon.ico" type="image/x-icon"><link href="/logo-safari.png?v=20170315" id="apple-touch-icon" rel="apple-touch-icon-precomposed"/><link href="https://www.sogou.com/sug/css/m3.min.v.7.css" rel="stylesheet" type="text/css"><link href="/new/pc/css/weixin-public-new.min.css?v=20170315" rel="stylesheet" type="text/css">

注：必须给url加上引号

(2)
代码：

#coding=utf-8import sys,urllib2,urllibdef addGETdata(url,data):    return url+'?'+urllib.urlencode(data)zipcode=sys.argv[1]url=addGETdata('http://www.weather.com.cn/cgi-bin/findweather/getForecast',[('query',zipcode)])print "using URL",urlreq=urllib2.Request(url)fd=urllib2.urlopen(req)while 1:    data=fd.read(1024)    if not len(data):        break    sys.stdout.write(data)

注：函数addGETdata(url,data)负责在url结尾添加所有的数据。在内部，他在URL和通过urllib.urlencode()得到的数据间添加问号。

POST方法：单独部分发送。URL永远不会被修改，附加信息通过第二个参数传递给urlopen().

(3)
代码：

#coding=utf-8import sys,urllib2,urllibzipcode=sys.argv[1]url='http://www.wunderground.com/cgi-bin/findweather/getForcecast'data=urllib.urlencode([('query',zipcode)])req=urllib2.Request(url)fd=urllib2.urlopen(req,data)while 1:    data=fd.read(1024)    if not len(data):        break    sys.stdout.write(data)

4.处理错误

(1)
代码：

#coding=utf-8import sys,urllib2req=urllib2.Request(sys.argv[1])try:    fd=urllib2.urlopen(req)except urllib2.URLError,e:    print "Error reteiveving data:",e    sys.exit(1)print "Retrieved",fd.geturl()info=fd.info()for key,value in info.items():    print "%s=%s"% (key,value)

运行结果：

D:\python\python.exe E:/code/python/unit6/error_basic.py
https://www.wunderground.com/cgi-bin/findweather/getForcecast
Error reteiveving data: HTTP Error 404: Not Found
Process finished with exit code 1

(2)
代码：

#coding=utf-8# import sys,urllib2## req=urllib2.Request(sys.argv[1])## try:#     fd=urllib2.urlopen(req)# except urllib2.URLError,e:#     print "Error reteiveving data:",e#     sys.exit(1)# print "Retrieved",fd.geturl()# info=fd.info()# for key,value in info.items():#     print "%s=%s"% (key,value)import sys,urllib2req=urllib2.Request(sys.argv[1])try:    fd=urllib2.urlopen(req)except urllib2.HTTPError,e:    print "Error reteiveving data:",e    print "Server error document follows:\n"    print e.read    sys.exit(1)except urllib2.URLError,e:    print "Error retriveving data",e    sys.exit(2)print "Retrieved",fd.geturl()info=fd.info()for key,value in info.items():    print "%s=%s"% (key,value)

运行结果：

D:\python\python.exe E:/code/python/unit6/error_basic.py
https://www.wunderground.com/cgi-bin/findweather/getForcecast
Error reteiveving data: HTTP Error 404: Not Found
Server error document follows:
<bound method _fileobject.read of >
Process finished with exit code 1

注：如果产生了一个HTTPEroor的实力，会捕获异常打印细节。否则，urllib2.URLError类的实例，会显示一条URLError信息。

读取数据错误：
通信错误，会使socket模块调用read()函数时发生socket.error;(会通过系统层传递)
没有通信情况下发送的文档被删节；

(3)
代码：

#coding=utf-8import sys,urllib2,socketreq=urllib2.Request(sys.argv[1])try:    fd=urllib2.urlopen(req)except urllib2.HTTPError,e:    print "Error retrieving data:",e    print "Sever error document follows:\n"    print e.read()    sys.exit(1)except urllib2.URLError,e:    print "Error retrieving data:",e    sys.exit(2)print "Retrieved",fd.geturl()bytesread=0while 1:    try:        data=fd.read(1024)    except socket.error,e:        print "Error reading data:",e        sys.exit(3)    if not len(data):        break    bytesread+=len(data)    sys.stdout.write(data)    if fd.info().has_key('Content-Length') and long(fd.info()['Content-Length'])!=long(bytesread):        print "Excepted a document of size %d,but read %d bytes"%(long(fd.info()['Content-Length']),bytesread)        sys.exit(4)

运行结果：

> D:\python\python.exe E:/code/python/unit6/erroe_all.py> https://www.wunderground.com/cgi-bin/findweather/getForcecast> Error retrieving data: HTTP Error 404: Not Found> Sever error document follows:> > > <!DOCTYPE html>> <!--[if IE 9]><html class="no-js ie9"> <![endif]-->> <!--[if gt IE 9]><!--> <html class="no-js "> <!--<![endif]-->>   <head>>       <title>Error | Weather Underground</title>>       <link href="//icons.wxug.com/" rel="dns-prefetch" />>       <link href="//api-ak.wunderground.com/" rel="dns-prefetch" />> <meta charset="utf-8">> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">

二、解析html和xhtml

第七章解析Html 和XHtml p151-p168
1.提取标题
代码：

#coding=utf-8from HTMLParser import HTMLParserimport sysclass TitleParser(HTMLParser):    def __init__(self):        self.title=''        self.readingtitle=0        HTMLParser.__init__(self)    def handle_starttag(self, tag, attrs):        if tag =='title':            self.readingtitle = 1    def handle_data(self, data):        if self.readingtitle:            self.title += data    def handle_endtag(self, tag):        if tag == 'title':            self.readingtitle = 0    def gettitle(self):        return self.titlefd = open(sys.argv[1])tp = TitleParser()tp.feed(fd.read())print "Title is:",tp.gettitle()

运行结果：

D:\python\python.exe E:/code/python/unit7/basic_title.py
E:/code/python/unit7/faqs.html
Title is: Appendix?B. MySQL 5.6 Frequently Asked Questions
Process finished with exit code 0

注：从表中摘取数据，或

2.改进
代码：

#coding=utf-8from HTMLParser import HTMLParserfrom htmlentitydefs import entitydefsimport sysclass TitleParser(HTMLParser):    def __init__(self):        self.title=''        self.readingtitle=0        HTMLParser.__init__(self)    def handle_starttag(self, tag, attrs):        if tag =='title':            self.readingtitle = 1    def handle_data(self, data):        if self.readingtitle:            self.title += data    def handle_endtag(self, tag):        if tag == 'title':            self.readingtitle = 0    def handle_entityref(self, name):        if entitydefs.has_key(name):            self.handle_data(entitydefs[name])        else:            self.handle_data('&'+name+';')    def gettitle(self):        return self.titlefd = open(sys.argv[1])tp = TitleParser()tp.feed(fd.read())print "Title is:",tp.gettitle()

etitle.html

<!DOCTYPE html><html ><head>    <title>Document Title &amp;Intro</title></head><body>this is my text.</body></html>

运行结果一：

D:\python\python.exe E:/code/python/unit7/basic_title.py
E:/code/python/unit7/etitle.html
Title is: Document Title Intro

Process finished with exit code 0
运行结果二：

D:\python\python.exe E:/code/python/unit7/etitle.py
E:/code/python/unit7/etitle.html
Title is: Document Title &Intro
Process finished with exit code 0

当一个实体出现时，代码检查该实体是否可以识别，可以，转换为相应得知，否则输入流中的文字；

3.转换字符参考
代码：

#coding=utf-8from HTMLParser import HTMLParserfrom htmlentitydefs import entitydefsimport sysclass TitleParser(HTMLParser):    def __init__(self):        self.title=''        self.readingtitle=0        HTMLParser.__init__(self)    def handle_starttag(self, tag, attrs):        if tag =='title':            self.readingtitle = 1    def handle_data(self, data):        if self.readingtitle:            self.title += data    def handle_endtag(self, tag):        if tag == 'title':            self.readingtitle = 0    def handle_entityref(self, name):        if entitydefs.has_key(name):            self.handle_data(entitydefs[name])        else:            self.handle_data('&'+name+';')    def handle_charref(self, name):        try:            charnum=int(name)        except ValueError:            return        if charnum<1 or charnum>225:            return        self.handle_data(chr(charnum))    def gettitle(self):        return self.titlefd = open(sys.argv[1])tp = TitleParser()tp.feed(fd.read())print "Title is:",tp.gettitle()

4.处理不均衡的标签
代码：

#coding=utf-8from HTMLParser import HTMLParserfrom htmlentitydefs import entitydefsimport sys,reclass TitleParser(HTMLParser):    def __init__(self):        self.taglevels=[]        self.handledtags=['title','ul','li']        self.processing=None        HTMLParser.__init__(self)    def handle_starttag(self, tag, attrs):        if len(self.taglevels) and self.taglevels[-1] == tag:            self.handle_endtag(tag)        self.taglevels.append(tag)        if tag in self.handledtags:            self.data = ''            self.processing = tag            if tag == 'ul':                print"List start"    def handle_data(self, data):        if self.processing:            self.data += data    def handle_endtag(self, tag):        if not tag in self.taglevels:            return        while len(self.taglevels):            starttag = self.taglevels.pop()            if starttag in self.handledtags:                self.finishprocessing(starttag)            if starttag == tag:                break    def cleanse(self):        self.data = re.sub('\s+', ' ', self.data)    def finishprocessing(self, tag):        self.cleanse()        if tag == 'title' and tag == self.processing:            print "Dom title", self.data        elif tag == 'ul':            print "List ended"        elif tag == 'li' and tag == self.processing:            print "List item", self.data        self.processing = None    def gettitle(self):        return self.title

处理特殊值，如果在映射表中有对应的，即采用映射的值，否则为字面值

 def handle_entityref(self, name):        if entitydefs.has_key(name):            self.handle_data(entitydefs[name])        else:            self.handle_data('&' + name + ';')    def handle_charref(self, name):        try:            charnum = int(name)        except ValueError:            return        if charnum < 1 or charnum > 255:            return        self.handle_data(chr(charnum))fd = open(sys.argv[1])tp = TitleParser()tp.feed(fd.read())

运行结果：

D:\python\python.exe E:/code/python/unit7/4un.py
E:/code/python/unit7/4un.html
Dom title DOCTYPE Title & Intro?
List start
List item First List item
List item second list item
List item second list item
List ended
Process finished with exit code 0

5.一个可以实际工作的例子

三、XML和XML-RPC

P169-p190
展示XML文档：tree,event.基于事件的解析器可以扫描文档，事件解析器可以响应。
8.2 使用Dom
代码：

#coding=utf-8from xml.dom import minidom,Nodedef scanNode(node,level=0):    msg = node.__class__.__name__    if node.nodeType == Node.ELEMENT_NODE:        msg += ",tag" + node.tagName    print " " * level * 4, msg    if node.hasChildNodes:        for child in node.childNodes:            scanNode(child, level + 1)doc = minidom.parse("Sample.xml")scanNode(doc)

运行结果：

D:\python\python.exe E:/code/python/unit8/un1.py

 Document>      Element,tagbook>          Text>          Element,tagtitle>              Text>          Text>          Element,tagauthor>              Text>              Element,tagname>                  Text>                  Element,tagfirst>                      Text>                  Text>                  Element,taglast>                      Text>                  Text>              Text>              Element,tagaffiliation>                  Text>              Text>          Text>          Element,tagchapter>              Text>              Element,tagtitle>                  Text>              Text>              Element,tagpara>                  Text>                  Element,tagcompany>                      Text>                  Text>              Text>          Text

Process finished with exit code 0

sample.xml

<?xml version="1.0" encoding="UTF-8"?><book>    <title> Sample XML Thing </title>    <author>        <name>            <first>Benjamin</first>            <last>Smith</last>        </name>        <affiliation>Springy Widgets,Inc.</affiliation>    </author>    <chapter number = "1">        <title>First chapter</title>        <para>            I think widgets are great.you should buy lots            of them from <company>Springy widgets,Inc</company>        </para>    </chapter></book>

2.使用dom完全解析
代码：

#coding=utf-8"""将XML以文本形式重新格式化输出1.使用Node的节点类型,判断下一步如何处理2.对不同的节点名(tagName)进行相应的处理"""from xml.dom import minidom, Nodeimport re, textwrapclass SampleScanner:    def __init__(self, doc):        for child in doc.childNodes:            if child.nodeType == Node.ELEMENT_NODE and child.tagName == "book":                """只处理book元素"""                self.handleBook(child)    def gettext(self, nodelist):        """获取当前节点的文本,        1.如果当前的节点为TEXT_NODE,将文本追加到列表中        2.如果当前的节点不是TEXT_NODE,递归地调用gettext"""        retlist = []        for node in nodelist:            if node.nodeType == Node.TEXT_NODE:                retlist.append(node.wholeText)            elif node.hasChildNodes:                retlist.append(self.gettext(node.childNodes))        return re.sub("\s+", " ", "".join(retlist))    def handleBook(self, node):        """处理Book节点        1.如果不是ELEMENT_NODE,不予理睬        2.如果是title,直接打印出文本内容        3.如果是author,调用handleAuthor,继续处理节点        4.如果是chapter,调用handleChapter,继续处理节点        """        for child in node.childNodes:            if child.nodeType != Node.ELEMENT_NODE:                continue            if child.tagName == "title":                print "Book title is :", self.gettext(child.childNodes)            if child.tagName == "author":                self.handleAuthor(child)            if child.tagName == "chapter":                self.handleChapter(child)    def handleAuthor(self, node):        """处理Autho节点        1.如果不是ELEMENT_NODE,不予理睬        2.如果是name,调用handleAuthoerName,继续处理节点        3.如果是affiliation,调用gettext,并打印出来        """        for child in node.childNodes:            if child.nodeType != Node.ELEMENT_NODE:                continue            if child.tagName == "name":                self.handleAuthorName(child)            elif child.tagName == "affiliation":                print "Author affiliation:", self.gettext([child])    def handleAuthorName(self, node):        """处理author.name节点        1.使用getElementsByTagName获得子节点        2.调用gettext得到子节点的文本,并打印处理        """        surname = self.gettext(node.getElementsByTagName("last"))        givenname = self.gettext(node.getElementsByTagName("first"))        print "Author Name:%s %s " % (surname, givenname)    def handleChapter(self, node):        """处理chapter节点        1.如果不是ELEMENT_NODE,不予理睬        2.如果是para,调用handlePara,继续处理        """        print "*** Start of Chapter %s,%s" % (        node.getAttribute("number"), self.gettext(node.getElementsByTagName("title")))        for child in node.childNodes:            if child.nodeType != Node.ELEMENT_NODE:                continue            if child.tagName == "para":                self.handlePara(child)    def handlePara(self, node):        """        1.获取当前节点的文本        2.调用textwrap格式化文本        """        paratext = self.gettext([node])        paratext = textwrap.fill(paratext)        print paratextdoc = minidom.parse("Sample.xml")SampleScanner(doc)

运行结果：

D:\python\python.exe E:/code/python/unit8/un2.py
Book title is : Sample XML Thing
Author Name:Smith Benjamin
Author affiliation: Springy Widgets,Inc.
*** Start of Chapter 1,First chapter
I think widgets are great.you should buy lots of them from Springy
widgets,Inc
Process finished with exit code 0

3.使用Dom产生文档
代码：

#coding=utf-8"""使用minidom生成XML1.创建Element,createElement2.添加子节点,appendChild3.创建Text,createTextNode4.创建属性,createAttribute"""from xml.dom import minidom,Node# 创建Documentdoc = minidom.Document()# 创建book节点book = doc.createElement("book")doc.appendChild(book)# 创建Title节点title = doc.createElement("title")text = doc.createTextNode("Sample XML Thing")title.appendChild(text)book.appendChild(title)# 创建author节点author = doc.createElement("author")# 创建name节点name = doc.createElement("name")first = doc.createElement("first")first.appendChild(doc.createTextNode("Benjamin"))name.appendChild(first)last = doc.createElement("last")last.appendChild(doc.createTextNode("Smith"))name.appendChild(last)author.appendChild(name)book.appendChild(author)# author节点完毕# 创建chapter节点chapter = doc.createElement("chapter")chapter.setAttribute("number","1")title = doc.createElement("title")title.appendChild(doc.createTextNode("Fisrt Chapter"))chapter.appendChild(title)para = doc.createElement("para")para.appendChild(doc.createTextNode("I think widgets are great.you should buy lots \of them from"))company = doc.createElement("company")company.appendChild(doc.createTextNode("Springy widgets,Inc"))para.appendChild(company)chapter.appendChild(para)# chapter节点完毕book.appendChild(chapter)# book节点完毕print doc.toprettyxml(indent = " ")

运行结果：

D:\python\python.exe E:/code/python/unit8/un3.py

<?xml version="1.0" ?><book> <title>Sample XML Thing</title> <author>  <name>   <first>Benjamin</first>   <last>Smith</last>  </name> </author> <chapter number="1">  <title>Fisrt Chapter</title>  <para>   I think widgets are great.you should buy lots of them from   <company>Springy widgets,Inc</company>  </para> </chapter></book>

Process finished with exit code 0

4.dom类型参考

8.3使用xml-rpc

代码：

#coding=utf-8import xmlrpcliburl='http://liandesinian.blog.51cto.com/7737219/1565474's=xmlrpclib.ServerProxy(url)catdata=s.meerkat.getCategories()cattiles=[item['title'] for item in catdata]cattiles.sort()for item in cattiles:    print item

运行结果：

D:\python\python.exe E:/code/python/unit8/un6.py
Process finished with exit code 0

代码：

#coding=utf-8import xmlrpclib,sys,textwrapclass NewsCat:    def __init__(self,catdata):        self.id=catdata['id']        self.title=catdata['title']    def __cmp__(self, other):        return cmp(self.title,other.title)class NewsSource:    def __init__(self,url='http://www.oreillynet.com/meerkat/xml-rpc/server.php'):        self.s=xmlrpclib.ServerProxy(url)        self.loadcats()    def loadcats(self):        print "Loading categories...."        catdata=self.s.meerkat.getCatgries()        self.cats=[NewsCat(item) for item in catdata]        self.cat.sort()    def displaycats(self):        numonline=0        i=0        for item in self.cats:            sys.stdout.write("%2d:%20.20s"%(i+1,item.title))            i+=1            numonline+=1            if numonline%3==0:                sys.stdout.write("\n")        if numonline!=0:            sys.stdout.write("\n")def promotcat(self):    sys.__displaycats()    sys.stdout.write("select a catgory or q to quit")    selection = sys.stdin.readline().strip()    if selection == 'q':        sys.exit(0)    return int(selection) - 1def dispact(self, cat):    items = self.s.meerkat.getItems({'category': cat,                                     'ids': 1,                                     'descriptions': 1,                                     'categories': 1,                                     'channels': 1,                                     'data': 1,                                     'num_items': 15})    if not len(items):        print "Sorry,no items in that category."        sys.stdout.write("Press Enter to continue:")        sys.stdin.readline()        return    while 1:        print self.dispitemsummary(items)        sys.stdout.write("select a catgory or q to quit")        selection = sys.stdin.readline().strip()        if selection=='q':             return        self.dispitem(items[int(selection)-1])def dispitemsummary(self, items):    counter = 0    for item in items:        print "%2d:%s"(counter + 1, item['title'])        counter += 1def dispitem(self, item):    print "---%s---" % item['title']    print "Posted on", item['data']    print "Description:"    print textwrap.fill(item['description'])    print "\nlink:", item['link']    sys.stdout.write("\nPress Enter to continue: ")    sys.stdin.readline()    n = NewsSource()    while 1:        cat = n.promotcat()        n.dispact(cat)

0 0