pythonTCP/IP编程

Posted 2020-12-02 嘉禾世兴

No1:

【TCP】

客户端

import socket

s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.connect((\'www.sina.com.cn\',80))
s.send(b\'GET / HTTP/1.1\\r\\nHost: www.sina.com.cn\\r\\nConnection:close\\r\\n\\r\\n\')

buffer=[]
while True:
    d=s.recv(1024)
    if d:
        buffer.append(d)
    else:
        break
data=b\'\'.join(buffer)

s.close()

header,html = data.split(b\'\\r\\n\\r\\n\',1)
print(header.decode(\'utf-8\'))
with open(\'sina.html\',\'wb\') as f:
    f.write(html)
    

运行结果得到一个sina.html文件，双击打开是新浪主页

服务端接受客户端

import socket,threading

s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.bind((\'127.0.0.1\',9999))
s.listen(5)
print(\'Waiting for connection...\')

def tcplink(sock,addr):
    print(\'Accept new connection from %s:%s...\' % addr)
    sock.send(b\'Welcome!\')
    while True:
        data = sock.recv(1024)
        time.sleep(1)
        if not data or data.decode(\'utf-8\')==\'exit\':
            break
        sock.send((\'Hello,%s\' % data.decode(\'utf-8\')).encode(\'utf-8\'))
    sock.close()
    print(\'Connection from %s:%s closed.\' % addr)
    
while True:
    sock,addr = s.accept()
    t=threading.Thread(target=tcplink,args=(sock,addr))
    t.start()

import socket

s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.connect((\'127.0.0.1\',9999))
print(s.recv(1024).decode(\'utf-8\'))
for data in [b\'Michael\',b\'Tracy\',b\'Sarah\']:
    s.send(data)
    print(s.recv(1024).decode(\'utf-8\'))
s.send(b\'exit\')
s.close()

No2：

【UDP】

服务端接受客户端

import socket

s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
s.bind((\'127.0.0.1\',9999))

print(\'Bind UDP on 9999....\')
while True:
    data,addr=s.recvfrom(1024)
    print(\'Received from %s:%s.\' % addr)
    s.sendto(b\'Hello,%s!\' % data,addr)

import socket

s=socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
for data in [b\'Michael\',b\'Tracy\',b\'Sarah\']:
    s.sendto(data,(\'127.0.0.1\',9999))
    print(s.recv(1024).decode(\'utf-8\'))
s.close()

运行结果

No3：

【SMTP发送邮件】

构造一个邮件对象就是一个Messag对象，如果构造一个MIMEText对象，就表示一个文本邮件对象，如果构造一个MIMEImage对象，就表示一个作为附件的图片，要把多个对象组合起来，就用MIMEMultipart对象，而MIMEBase可以表示任何对象。

from email import encoders
from email.header import Header
from email.mime.text import MIMEText
from email.utils import parseaddr,formataddr

import smtplib

def _format_addr(s):
    name,addr=parseaddr(s)
    return formataddr((Header(name,\'utf-8\').encode(),addr))
    
from_addr=input(\'From:\')
password=input(\'Password:\')
to_addr=input(\'To:\')
smtp_server=input(\'SMTP server:\')

msg=MIMEText(\'hello,send by Python...\',\'plain\',\'utf-8\')
msg[\'From\']=_format_addr(\'Python爱好者<%s>\' % from_addr)
msg[\'To\']=_format_addr(\'管理员<%s>\' % to_addr)
msg[\'Subject\']=Header(\'来自SMTP的问候。。。\',\'utf-8\').encode()

server=smtplib.SMTP(smtp_server,25)
server.set_debuglevel(1)
server.login(from_addr,password)
server.sendmail((from_addr,[to_addr],msg.as_string()))
server.quit()

发送附件

msg=MIMEMultipart()
msg[\'From\']=_format_addr(\'Python爱好者<%s>\'%from_addr)
msg[\'To\']=_format_addr(\'管理员<%s>\'%to_addr)
msg[\'Subject\']=Header(\'来自SMTP的问候。。。\',\'utf-8\').encode()

msg.attach(MIMEText(\'send with file...\',\'plain\',\'utf-8\'))

with open(\'/Users/michael/Download/test.png\',\'rb\') as f:
    mime=MIMEBase(\'image\',\'png\',filename=\'test.png\')
    mime.add_header(\'Content-Disposition\',\'attachment\',filename=\'test.png\')
    mime.add_header(\'Content-ID\',\'<0>\')
    mime.add_header(\'X-Attachment-Id\',\'0\')
    mime.set_payload(f.read())
    encoders.encode_base64(mime)
    msg.attach(mime)

No4：

【Pop3接收邮件】

Python的poplib模块收取邮件分两步：第一步是用POP3协议把邮件获取到本地，第二步是用email模块把原始邮件解析为Message对象，然后，用适当的形式把邮件内容展示给用户即可。

先接收

import poplib

email=input(\'Email:\')
password=input(\'Password:\')
pop3_server=input(\'POP3 server:\')

server=poplib.POP3(pop3_server)
server.set_debuglevel(1)
print(server.getwelcome().decode(\'utf-8\'))

server.user(email)
server.pass_(password)

print(\'Message:%s. Size:%s\' % server.stat())
resp,mails,octets=server.list()
print(mails)

index=len(mails)
resp,lines,octets=server.retr(index)

msg_content=b\'\\r\\n\'.join(lines).decode(\'utf-8\')
msg=Parser().parsestr(msg_content)

server.quit()

再解析

from email.parser import Parser
from email.header import decode_header
from email.utils import parseaddr

import poplib

msg=Parser().parsestr(msg_content)

def print_info(msg,indent=0):
    if indent==0:
        for header in [\'From\',\'To\',\'Subject\']:
            value=msg.get(header,\'\')
            if value:
                if header == \'Subject\':
                    value = decode_str(value)
                else:
                    hdr,addr=parseaddr(value)
                    name=decode_str(hdr)
                    value=u\'%s<%s>\' % (name,addr)
            print(\'%s%s: %s\' % (\'  \' * indent,header,value))
    if(msg,is_multipart()):
        parts=msg.get_payload()
        for n,part in enumerate(parts):
            print(\'%spart %s\' % (\'  \' * indent,n))
            print(\'%s------------------\' % (\'   \' * indent))
            print_info(part,indent+1)
    else:
        content_type=msg.get_content_type()
        if content_type==\'text/plan\' or content_type==\'text/html\':
            content=msg.get_payload(decode=True)
            charset=guess_charset(msg)
            if charset:
                content=content.decode(charset)
            print(\'%sText: %s\' % (\'   \' * indent,content + \'...\'))
        else:
            print(\'%sAttachment: %s\' % (\'  \' * indent,content_type))
            
def decode_str(s):
    value,charset = decode_header(s)[0]
    if charset:
        value = value.decode(charset)
    return value
    
def guess_charset(msg):
    charset=msg.get_charset()
    if charset is None:
        content_type=msg.get(\'Content-Type\',\'\').lower()
        pos=content_type.find(\'charset=\')
        if pos >= 0:
            charset=content_type[pos + 8].strip()
    return charset