python网络编程学习笔记（一）

时间 2019-12-08

原文原文链接

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2.7.5php

第一部分底层网络css

1、笔记

#coding=utf-8
第一章

import socket,sys
port=70
print (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html

import socket,sys
port=70
print (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,sys
port=70
host=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)

基本服务器操做node

import socket

host=''
port=80

s=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."% port

while 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python

import gopherlib,sys
host=sys.argv[1]
file=sys.argv[2]

f=gopherlib.send_selector(file,host)
for line in f.readlines():
    sys.stdout.write(line)

import urllib,sys
host=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,sys
f=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udpweb

第三章网络服务器chrome

import socket
solist=[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apache

import sys,socket

result=socket.getaddrinfo(sys.argv[1],None)
print result[0][4]

import sys,socket

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

P70
import sys,socket
result=socket.getaddrinfo(sys.argv[1],None,0,socket.SOCK_STREAM)
counter=0
for item in result:
    print "%-2d:%s"%(counter,item[4])
    counter+=1

执行反向查询编程

import sys,socket

try:
    result=socket.gethostbyaddr(sys.argv[1])

    print "Primary hostname:"
    print " "+result[0]

    print "\nAddresses:"
    for item in result[2]:
        print " "+item

except socket.herror,e:
    print "Couldn't look up name:",e

正反向查询api

import sys,socket
def 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

得到完整域名，gethostname()得到主机名，getfqdn()得到完整信息，getaddrinfo()得到该域名对性的IP地址。

import sys,socket

def 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:",hostname

print "Fully-qualified name:",socket.getfqdn(hostname)
try:
    print "IP addresses:",",".join(getipaddrs(hostname))
except socket.gaierror,e:
    print "Couldn't not get IP addresses:",e

import sys,DNS
query=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,DNS

def hierquery(qstring,qtype):#给出主机名的相应服务器
    reqobj=DNS.Request()#创建查询对象实例
    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,traceback

host = ''
port = 51432

s = 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,sys

def 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))+data

print "Enter a string:"
str=sys.stdin.readline().rstrip()

print repr(sendstring(str))


import socket,sys

host,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,sys

def 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 Address
bindserver.py

import socket,traceback

host = '127.0.0.1'
port = 51423


s = 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,select


port = 51423
host = 'localhost'

spinsize = 10
spinpos = 0
spindir = 1

def 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 = -1

s = 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.py

import socket,sys,select

port = 51423
host = 'localhost'

spinsize = 10
spinpos = 0
spindir = 1

def 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 = -1

s = 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()

2、TCP通讯方式

服务端：

#coding=utf-8
from socket import*

#监听套接字的链接和回应
#服务器端
myHost='' #‘’表明主机全部可用端口
myPort=50007

sockobj=socket(AF_INET,SOCK_STREAM)#建立一个TCP scoket 对象
sockobj.bind((myHost,myPort))#绑定服务端口号
sockobj.listen(5)#监听，容许5个挂起链接

while True:#一直监听直到进程被杀死
    connection,address=sockobj.accept()#等待下个客户端链接
    print('Server connected by：',address)#链接是新的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-8
import socket

#客户端
import sys
from socket import *
serverHost='localhost'
serverPort=50007

message=[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()

3、UDP通讯方式

UDP请求端：

#coding=utf-8
import socket,sys

host=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-8
import socket,traceback

host=''
port=54132

s=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-8
import socket,traceback,time,struct

host=''
port=51432

s=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-8
import socket,sys,struct,time
hostname='localhost'
port=51432

host=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-=220898800
print time.ctime(int(secs))
超时：
#coding=utf-8
import socket,traceback

host = ''
port = 51432

s = 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()
4、ftp
#coding=utf-8
#自动抓取并打开远程文件文件
import os,sys
from getpass import getpass
from ftplib import FTP

nonpassive=False
filename='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)

5、广播

接收端：

#coding=utf-8
import socket,traceback

host = ''
port = 51423

s = 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-8
import socket,sys
dest = ('<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

1、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协议通讯

1.下载Web界面

(1)

#coding=utf-8
import sys,urllib2

req=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。相似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-8
import sys,urllib2

req=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)

运行结果以下：
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()获得的值与传入Request的对象不一样，结尾处多了一条斜线，远程服务器作了一个Http转向，urllib自动跟随了转向。
其余行显示Http的header信息；

2.在远程HTTP服务器上验证

(1)

#coding=utf-8
import sys,urllib2,getpass

class 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 ret
req = urllib2.Request(sys.argv[1])
opener = urllib2.build_opener(urllib2.HTTPBasicAuthHandler(TerminalPassword()))
response = opener.open(req)
print response.read()

扩展urllib2.HTTPPasswordMgr类，容许程序在须要的时候像操做员询问用户名和密码，
build_opener：容许指定额外的处理程序，代码须要支持认证，因此HTTPBasicAuthHandler加处处理连接

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。每一个键和值对用“&”分割，有些字符须要被避免。不适合数据量比较大的地方。

(1)

代码：
#coding=utf-8
import sys,urllib2

req=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。相似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

<!doctype html>

注：必须给url加上引号

(2)
代码：

#coding=utf-8
import sys,urllib2,urllib

def 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",url
req=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结尾添加全部的数据。在内部，他在URL和经过urllib.urlencode()获得的数据间添加问号。

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

(3)
代码：

#coding=utf-8
import sys,urllib2,urllib

zipcode=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-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)

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,urllib2

req=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 <socket._fileobject object at
0x0216A5B0>>

Process finished with exit code 1

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

读取数据错误：
通讯错误，会使socket模块调用read()函数时发生socket.error;(会经过系统层传递)
没有通讯状况下发送的文档被删节；

(3)
代码：

#coding=utf-8
import sys,urllib2,socket

req=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=0

while 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">

2、解析html和xhtml

第七章解析Html 和XHtml p151-p168
1.提取标题
代码：

#coding=utf-8
from HTMLParser import HTMLParser
import sys

class 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.title

fd = 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-8
from HTMLParser import HTMLParser
from htmlentitydefs import entitydefs
import sys

class 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.title

fd = 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能够识别，能够，转换为相应得知，不然输入流中的文字；

3.转换字符参考
代码：

#coding=utf-8
from HTMLParser import HTMLParser
from htmlentitydefs import entitydefs
import sys

class 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.title

fd = 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-8
from HTMLParser import HTMLParser
from htmlentitydefs import entitydefs
import sys,re

class 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，若是在映射表中有对应的，即采用映射的值，不然为字面值

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

5.一个能够实际工做的例子

3、XML和XML-RPC

P169-p190
展现XML文档：tree,event.基于事件的解析器能够扫描文档，事件解析器能够响应。
8.2 使用Dom
代码：

#coding=utf-8
from xml.dom import minidom,Node

def 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彻底解析
代码：

#coding=utf-8
"""
将XML以文本形式从新格式化输出
1.使用Node的节点类型,判断下一步如何处理
2.对不一样的节点名(tagName)进行相应的处理
"""
from xml.dom import minidom, Node
import re, textwrap


class 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.若是当前的节点为TEXT_NODE,将文本追加到列表中
        2.若是当前的节点不是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.若是不是ELEMENT_NODE,不予理睬
        2.若是是title,直接打印出文本内容
        3.若是是author,调用handleAuthor,继续处理节点
        4.若是是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.若是不是ELEMENT_NODE,不予理睬
        2.若是是name,调用handleAuthoerName,继续处理节点
        3.若是是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得到子节点
        2.调用gettext获得子节点的文本,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.若是不是ELEMENT_NODE,不予理睬
        2.若是是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 paratext


doc = 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XML
1.建立Element,createElement
2.添加子节点,appendChild
3.建立Text,createTextNode
4.建立属性,createAttribute
"""
from xml.dom import minidom,Node

# 建立Document
doc = minidom.Document()
# 建立book节点
book = doc.createElement("book")
doc.appendChild(book)
# 建立Title节点
title = doc.createElement("title")
text = doc.createTextNode("Sample XML Thing")
title.appendChild(text)
book.appendChild(title)
# 建立author节点
author = doc.createElement("author")
# 建立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

# 建立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-8
import xmlrpclib
url='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-8
import xmlrpclib,sys,textwrap

class 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) - 1


def 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 += 1


def 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)