Foundations of Python Network Programming

537 Pages·2007·4.01 MB·English

by  John Goerzen

Goerzen_3715 front.fm Page i Sunday, July 18, 2004 6:36 AM
Foundations of Python
Network Programming
JOHN GOERZEN
Goerzen_3715 front.fm Page ii Sunday, July 18, 2004 6:36 AM
Foundations of Python Network Programming
Copyright © 2004 by John Goerzen
All rights reserved. No part of this work may be reproduced or transmitted in any form or by any
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To my wife Terah: Thank you for tolerating the tall grass,
late evenings, and short weekends while I worked on this book.
Thank you for supporting me every step ofthe way with
encouragement, love, and chocolate cake.

Contents at a Glance
About the Author xv
About the Technical Reviewer xvii
Acknowledgments xix
Introduction xxi
Part One Low- Level Networking
1
Chapter 1 Introduction to Client/Server Networking 3
Chapter 2 Network Clients 19
Chapter 3 Network Servers 35
Chapter 4 Domain Name System 65
Chapter 5 Advanced Network Operations 87
Part Two Web Services 111
Chapter 6 Web Client Access 113
Chapter 7 Parsing HTML and XHTML 127
Chapter 8 XML and XML -RPC 145
Part Three E-mail Services
167
Chapter 9 E-Mail Composition
and Decoding 169
Chapter 10 Simple Message Transport Protocol 197
Chapter 11 POP 211
Chapter 12 IMAP 223
Part Four General-Purpose Client Protocols
273
Chapter 13 FTP 275
Chapter 14 Database Clients 295
Chapter 15 SSL 321
v
Contentsata Glance
Part Five Server-Side Frameworks
339
Chapter 16 SocketServer 341
Chapter 17 SimpleXMLRPCServer 355
Chapter 18 CGI 369
Chapter 19 mod_python 393
Part Six Multitasking
417
Chapter 20 Forking 419
Chapter 21 Threading 443
Chapter 22 Asynchronous Communication 469
Index 491
vi
Contents
About the Author xv
About the Technical Reviewer xvii
Acknowledgments xix
Introduction xxi
Part One Low- Level Networking 1
Chapter 1 Introduction to
Client/Server Networking
3
Understanding TCP Basics 3
Using the Client/Server Model
6
Understanding User Datagram Protocol 7
Understanding Physical Transports and Ethernet 9
Networking in Python 9
Summary 17
Chapter 2 Network Clients 19
Understanding Sockets 19
Creating Sockets 20
Communicating with Sockets 23
Handling Errors 23
Using User Datagram Protocol
31
Summary
34
vii
Contents
Chapter 3 Network Servers 35
Preparing for Connections 35
Accepting Connections
40
Handling Errors 41
Using User Datagram Protocol
43
Using inetd or xinetd 45
Logging with syslog 55
Avoiding Deadlock
60
Summary
63
Chapter 4 Domain Name System
65
Making DNS Queries
65
Using Operating System Lookup Services
66
Using PyDNS for Advanced Lookups 76
Summary 85
Chapter 5 Advanced Network Operations 87
Half-Open Sockets
87
Timeouts
89
Transmitting Strings
90
Understanding Network Byte Order
93
Using Broadcast Data
95
Working with IPv6
97
Binding to Specific Addresses
102
Using Event Notification with poll() or select()
104
Summary
109
Part Two Web Services
111
Chapter 6 Web Client Access
113
Fetching Web Pages 114
Authenticating 115
Submitting Form Data 118
Handling Errors 121
Using Non-HTTP Protocols : 125
Summary 125
viii
Contents
Chapter 7 Parsing HTML and XHTML 127
Understanding Basic HTML Parsing 128
Handling Real-World HTML 130
A Working Example 137
Summary 143
Chapter 8 XML and XML -RPC 145
Understanding XML Documents 147
Using DOM 148
Using XML-RPC 159
Summary 166
Part Three E-mail Services 167
Chapter 9 E-Mail Composition and Decoding 169
Understanding Traditional Messages 169
Composing Traditional Messages 173
Parsing Traditional Messages 176
Understanding MIME 180
Composing MIME Attachments 182
Composing MIME Alternatives 185
Composing Non-English Headers 187
Composing Nested Multiparts 188
Parsing MIME Messages 190
Summary 195
Chapter 10 Simple Message Transport Protocol 197
Introducing the SMTP Library 197
Error Handling and Conversation Debugging 199
Getting Information from EHLO 202
Using Secure Sockets Layer and Transport Layer Security 205
Authenticating 208
SMTP Tips 209
Summary 210
ix