Python Pocket Reference, Second Edition

Internet Modules and Tools

This section summarizes Python’s support for Internet scripting.

Commonly Used Library Modules

Following are some of the more commonly used modules in the Python Internet modules set. This is just a representative sample; see the Python Library Reference for a more complete list.

socket

Low-level network communications support (TCP/IP, UDP, etc.). Interfaces for sending and receiving data over BSD-style sockets: socket.socket( ) makes an object with socket call methods (e.g., object.bind( )). Most protocol and server modules use this module internally.

select

Interfaces to Unix and Windows select function. Waits for activity on one of N files or sockets. Commonly used to multiplex among multiple streams, or to implement timeouts. Only works for sockets on Windows, not files.

cgi

Server-side CGI script support: cgi.FieldStorage parses the input stream; cgi.escape applies HTML escape conventions to output streams. To parse and access form information: after a CGI script calls form=cgi.FieldStorage( ), form is a dictionary-like object with one entry per form field (e.g., form["name"].value is form field name text).

urllib, urllib2

Fetches web pages and server script outputs from their Internet addresses (URLs): urllib.urlopen(url) returns file with read methods; also urllib.urlretrieve(remote, local). Supports HTTP, FTP, gopher, local file URLs. Also has tools for escaping URL text: urllib.quote_plus(str) does URL escapes for text inserted into HTML output streams. ...