<!DOCTYPE html PUBLIC
"-//W3C//DTD HTML 4.0 Transitional//EN">
<link rel=
"STYLESHEET" href=
"lib.css" type='text/css'
/>
<link rel=
"SHORTCUT ICON" href=
"../icons/pyfav.png" type=
"image/png" />
<link rel='start' href='../index.html' title='Python Documentation Index'
/>
<link rel=
"first" href=
"lib.html" title='Python Library Reference'
/>
<link rel='contents' href='contents.html'
title=
"Contents" />
<link rel='index' href='genindex.html' title='Index'
/>
<link rel='last' href='about.html' title='About this document...'
/>
<link rel='help' href='about.html' title='About this document...'
/>
<link rel=
"prev" href=
"posix-large-files.html" />
<link rel=
"parent" href=
"module-posix.html" />
<link rel=
"next" href=
"module-pwd.html" />
<meta name='aesop' content='information'
/>
<title>8.1.2 Module Contents
</title>
<div id='top-navigation-panel' xml:id='top-navigation-panel'
>
<table align=
"center" width=
"100%" cellpadding=
"0" cellspacing=
"2">
<td class='online-navigation'
><a rel=
"prev" title=
"8.1.1 Large File Support"
href=
"posix-large-files.html"><img src='../icons/previous.png'
border='
0' height='
32' alt='Previous Page' width='
32'
/></A></td>
<td class='online-navigation'
><a rel=
"parent" title=
"8.1 posix "
href=
"module-posix.html"><img src='../icons/up.png'
border='
0' height='
32' alt='Up One Level' width='
32'
/></A></td>
<td class='online-navigation'
><a rel=
"next" title=
"8.2 pwd "
href=
"module-pwd.html"><img src='../icons/next.png'
border='
0' height='
32' alt='Next Page' width='
32'
/></A></td>
<td align=
"center" width=
"100%">Python Library Reference
</td>
<td class='online-navigation'
><a rel=
"contents" title=
"Table of Contents"
href=
"contents.html"><img src='../icons/contents.png'
border='
0' height='
32' alt='Contents' width='
32'
/></A></td>
<td class='online-navigation'
><a href=
"modindex.html" title=
"Module Index"><img src='../icons/modules.png'
border='
0' height='
32' alt='Module Index' width='
32'
/></a></td>
<td class='online-navigation'
><a rel=
"index" title=
"Index"
href=
"genindex.html"><img src='../icons/index.png'
border='
0' height='
32' alt='Index' width='
32'
/></A></td>
<div class='online-navigation'
>
<b class=
"navlabel">Previous:
</b>
<a class=
"sectref" rel=
"prev" href=
"posix-large-files.html">8.1.1 Large File Support
</A>
<b class=
"navlabel">Up:
</b>
<a class=
"sectref" rel=
"parent" href=
"module-posix.html">8.1 posix
</A>
<b class=
"navlabel">Next:
</b>
<a class=
"sectref" rel=
"next" href=
"module-pwd.html">8.2 pwd
</A>
<!--End of Navigation Panel-->
<H2><A NAME=
"SECTION0010120000000000000000"></A><A NAME=
"posix-contents"></A>
Module
<tt class=
"module">posix
</tt> defines the following data item:
<dl><dt><b><tt id='l2h-
2971' xml:id='l2h-
2971'
>environ
</tt></b></dt>
A dictionary representing the string environment at the time the
interpreter was started. For example,
<code>environ['HOME']
</code> is the
pathname of your home directory, equivalent to
<code>getenv(
"HOME")
</code> in C.
Modifying this dictionary does not affect the string environment
passed on by
<tt class=
"function">execv()
</tt>,
<tt class=
"function">popen()
</tt> or
<tt class=
"function">system()
</tt>; if you need to change the environment, pass
<code>environ
</code> to
<tt class=
"function">execve()
</tt> or add variable assignments and
export statements to the command string for
<tt class=
"function">system()
</tt> or
<tt class=
"function">popen()
</tt>.
<span class=
"note"><b class=
"label">Note:
</b>
The
<tt class=
"module"><a href=
"module-os.html">os
</a></tt> module provides an alternate
implementation of
<code>environ
</code> which updates the environment on
modification. Note also that updating
<code>os.environ
</code> will render
this dictionary obsolete. Use of the
<tt class=
"module"><a href=
"module-os.html">os
</a></tt> module version of
this is recommended over direct access to the
<tt class=
"module">posix
</tt> module.
</span>
Additional contents of this module should only be accessed via the
<tt class=
"module"><a href=
"module-os.html">os
</a></tt> module; refer to the documentation for that module for
<div class='online-navigation'
>
<table align=
"center" width=
"100%" cellpadding=
"0" cellspacing=
"2">
<td class='online-navigation'
><a rel=
"prev" title=
"8.1.1 Large File Support"
href=
"posix-large-files.html"><img src='../icons/previous.png'
border='
0' height='
32' alt='Previous Page' width='
32'
/></A></td>
<td class='online-navigation'
><a rel=
"parent" title=
"8.1 posix "
href=
"module-posix.html"><img src='../icons/up.png'
border='
0' height='
32' alt='Up One Level' width='
32'
/></A></td>
<td class='online-navigation'
><a rel=
"next" title=
"8.2 pwd "
href=
"module-pwd.html"><img src='../icons/next.png'
border='
0' height='
32' alt='Next Page' width='
32'
/></A></td>
<td align=
"center" width=
"100%">Python Library Reference
</td>
<td class='online-navigation'
><a rel=
"contents" title=
"Table of Contents"
href=
"contents.html"><img src='../icons/contents.png'
border='
0' height='
32' alt='Contents' width='
32'
/></A></td>
<td class='online-navigation'
><a href=
"modindex.html" title=
"Module Index"><img src='../icons/modules.png'
border='
0' height='
32' alt='Module Index' width='
32'
/></a></td>
<td class='online-navigation'
><a rel=
"index" title=
"Index"
href=
"genindex.html"><img src='../icons/index.png'
border='
0' height='
32' alt='Index' width='
32'
/></A></td>
<div class='online-navigation'
>
<b class=
"navlabel">Previous:
</b>
<a class=
"sectref" rel=
"prev" href=
"posix-large-files.html">8.1.1 Large File Support
</A>
<b class=
"navlabel">Up:
</b>
<a class=
"sectref" rel=
"parent" href=
"module-posix.html">8.1 posix
</A>
<b class=
"navlabel">Next:
</b>
<a class=
"sectref" rel=
"next" href=
"module-pwd.html">8.2 pwd
</A>
<span class=
"release-info">Release
2.4.2, documentation updated on
28 September
2005.
</span>
<!--End of Navigation Panel-->
See
<i><a href=
"about.html">About this document...
</a></i> for information on suggesting changes.