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

#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

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)

基本服务器操作

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

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udp

第三章 网络服务器

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

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

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

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

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,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()#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,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()

服务端：

#coding=utf-8
from 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=50007

sockobj=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-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()

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()
四、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)

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)