<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="X-UA-Compatible" content="IE=Edge" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>28.3. venv — Creation of virtual environments — Python 3.5.7 documentation</title>
<link rel="stylesheet" href="../_static/pydoctheme.css" type="text/css" />
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
<script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script>
<script type="text/javascript" src="../_static/jquery.js"></script>
<script type="text/javascript" src="../_static/underscore.js"></script>
<script type="text/javascript" src="../_static/doctools.js"></script>
<script type="text/javascript" src="../_static/language_data.js"></script>
<script type="text/javascript" src="../_static/sidebar.js"></script>
<link rel="search" type="application/opensearchdescription+xml"
title="Search within Python 3.5.7 documentation"
href="../_static/opensearch.xml"/>
<link rel="author" title="About these documents" href="../about.html" />
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<link rel="copyright" title="Copyright" href="../copyright.html" />
<link rel="next" title="28.4. zipapp — Manage executable python zip archives" href="zipapp.html" />
<link rel="prev" title="28.2. ensurepip — Bootstrapping the pip installer" href="ensurepip.html" />
<link rel="shortcut icon" type="image/png" href="../_static/py.png" />
<link rel="canonical" href="https://docs.python.org/3/library/venv.html" />
<script type="text/javascript" src="../_static/copybutton.js"></script>
</head><body>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="../py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="zipapp.html" title="28.4. zipapp — Manage executable python zip archives"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="ensurepip.html" title="28.2. ensurepip — Bootstrapping the pip installer"
accesskey="P">previous</a> |</li>
<li><img src="../_static/py.png" alt=""
style="vertical-align: middle; margin-top: -1px"/></li>
<li><a href="https://www.python.org/">Python</a> »</li>
<li>
<a href="../index.html">3.5.7 Documentation</a> »
</li>
<li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li>
<li class="nav-item nav-item-2"><a href="distribution.html" accesskey="U">28. Software Packaging and Distribution</a> »</li>
<li class="right">
<div class="inline-search" style="display: none" role="search">
<form class="inline-search" action="../search.html" method="get">
<input placeholder="Quick search" type="text" name="q" />
<input type="submit" value="Go" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
<script type="text/javascript">$('.inline-search').show(0);</script>
|
</li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<div class="section" id="module-venv">
<span id="venv-creation-of-virtual-environments"></span><h1>28.3. <a class="reference internal" href="#module-venv" title="venv: Creation of virtual environments."><code class="xref py py-mod docutils literal notranslate"><span class="pre">venv</span></code></a> — Creation of virtual environments<a class="headerlink" href="#module-venv" title="Permalink to this headline">¶</a></h1>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.3.</span></p>
</div>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.5/Lib/venv/">Lib/venv/</a></p>
<hr class="docutils" id="index-0" />
<p>The <a class="reference internal" href="#module-venv" title="venv: Creation of virtual environments."><code class="xref py py-mod docutils literal notranslate"><span class="pre">venv</span></code></a> module provides support for creating lightweight “virtual
environments” with their own site directories, optionally isolated from system
site directories. Each virtual environment has its own Python binary (allowing
creation of environments with various Python versions) and can have its own
independent set of installed Python packages in its site directories.</p>
<p>See <span class="target" id="index-1"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0405"><strong>PEP 405</strong></a> for more information about Python virtual environments.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The <code class="docutils literal notranslate"><span class="pre">pyvenv</span></code> script has been deprecated as of Python 3.6 in favor of using
<code class="docutils literal notranslate"><span class="pre">python3</span> <span class="pre">-m</span> <span class="pre">venv</span></code> to help prevent any potential confusion as to which
Python interpreter a virtual environment will be based on.</p>
</div>
<div class="section" id="creating-virtual-environments">
<h2>28.3.1. Creating virtual environments<a class="headerlink" href="#creating-virtual-environments" title="Permalink to this headline">¶</a></h2>
<p>Creation of <a class="reference internal" href="#venv-def"><span class="std std-ref">virtual environments</span></a> is done by executing the
<code class="docutils literal notranslate"><span class="pre">pyvenv</span></code> script:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">pyvenv</span> <span class="o">/</span><span class="n">path</span><span class="o">/</span><span class="n">to</span><span class="o">/</span><span class="n">new</span><span class="o">/</span><span class="n">virtual</span><span class="o">/</span><span class="n">environment</span>
</pre></div>
</div>
<p>Running this command creates the target directory (creating any parent
directories that don’t exist already) and places a <code class="docutils literal notranslate"><span class="pre">pyvenv.cfg</span></code> file in it
with a <code class="docutils literal notranslate"><span class="pre">home</span></code> key pointing to the Python installation the command was run
from. It also creates a <code class="docutils literal notranslate"><span class="pre">bin</span></code> (or <code class="docutils literal notranslate"><span class="pre">Scripts</span></code> on Windows) subdirectory
containing a copy of the <code class="docutils literal notranslate"><span class="pre">python</span></code> binary (or binaries, in the case of
Windows). It also creates an (initially empty) <code class="docutils literal notranslate"><span class="pre">lib/pythonX.Y/site-packages</span></code>
subdirectory (on Windows, this is <code class="docutils literal notranslate"><span class="pre">Lib\site-packages</span></code>).</p>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<p class="last"><a class="reference external" href="https://packaging.python.org/en/latest/installing/#creating-virtual-environments">Python Packaging User Guide: Creating and using virtual environments</a></p>
</div>
<p>On Windows, you may have to invoke the <code class="docutils literal notranslate"><span class="pre">pyvenv</span></code> script as follows, if you
don’t have the relevant PATH and PATHEXT settings:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>c:\Temp>c:\Python35\python c:\Python35\Tools\Scripts\pyvenv.py myenv
</pre></div>
</div>
<p>or equivalently:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>c:\Temp>c:\Python35\python -m venv myenv
</pre></div>
</div>
<p>The command, if run with <code class="docutils literal notranslate"><span class="pre">-h</span></code>, will show the available options:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear]
[--upgrade] [--without-pip]
ENV_DIR [ENV_DIR ...]
Creates virtual Python environments in one or more target directories.
positional arguments:
ENV_DIR A directory to create the environment in.
optional arguments:
-h, --help show this help message and exit
--system-site-packages Give the virtual environment access to the system
site-packages dir.
--symlinks Try to use symlinks rather than copies, when symlinks
are not the default for the platform.
--copies Try to use copies rather than symlinks, even when
symlinks are the default for the platform.
--clear Delete the contents of the environment directory if it
already exists, before environment creation.
--upgrade Upgrade the environment directory to use this version
of Python, assuming Python has been upgraded in-place.
--without-pip Skips installing or upgrading pip in the virtual
environment (pip is bootstrapped by default)
</pre></div>
</div>
<p>Depending on how the <code class="docutils literal notranslate"><span class="pre">venv</span></code> functionality has been invoked, the usage message
may vary slightly, e.g. referencing <code class="docutils literal notranslate"><span class="pre">pyvenv</span></code> rather than <code class="docutils literal notranslate"><span class="pre">venv</span></code>.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>Installs pip by default, added the <code class="docutils literal notranslate"><span class="pre">--without-pip</span></code> and <code class="docutils literal notranslate"><span class="pre">--copies</span></code>
options</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>In earlier versions, if the target directory already existed, an error was
raised, unless the <code class="docutils literal notranslate"><span class="pre">--clear</span></code> or <code class="docutils literal notranslate"><span class="pre">--upgrade</span></code> option was provided. Now,
if an existing directory is specified, its contents are removed and
the directory is processed as if it had been newly created.</p>
</div>
<p>The created <code class="docutils literal notranslate"><span class="pre">pyvenv.cfg</span></code> file also includes the
<code class="docutils literal notranslate"><span class="pre">include-system-site-packages</span></code> key, set to <code class="docutils literal notranslate"><span class="pre">true</span></code> if <code class="docutils literal notranslate"><span class="pre">venv</span></code> is
run with the <code class="docutils literal notranslate"><span class="pre">--system-site-packages</span></code> option, <code class="docutils literal notranslate"><span class="pre">false</span></code> otherwise.</p>
<p>Unless the <code class="docutils literal notranslate"><span class="pre">--without-pip</span></code> option is given, <a class="reference internal" href="ensurepip.html#module-ensurepip" title="ensurepip: Bootstrapping the "pip" installer into an existing Python installation or virtual environment."><code class="xref py py-mod docutils literal notranslate"><span class="pre">ensurepip</span></code></a> will be
invoked to bootstrap <code class="docutils literal notranslate"><span class="pre">pip</span></code> into the virtual environment.</p>
<p>Multiple paths can be given to <code class="docutils literal notranslate"><span class="pre">pyvenv</span></code>, in which case an identical
virtualenv will be created, according to the given options, at each
provided path.</p>
<p>Once a venv has been created, it can be “activated” using a script in the
venv’s binary directory. The invocation of the script is platform-specific:</p>
<table border="1" class="docutils">
<colgroup>
<col width="18%" />
<col width="24%" />
<col width="58%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Platform</th>
<th class="head">Shell</th>
<th class="head">Command to activate virtual environment</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Posix</td>
<td>bash/zsh</td>
<td>$ source <venv>/bin/activate</td>
</tr>
<tr class="row-odd"><td> </td>
<td>fish</td>
<td>$ . <venv>/bin/activate.fish</td>
</tr>
<tr class="row-even"><td> </td>
<td>csh/tcsh</td>
<td>$ source <venv>/bin/activate.csh</td>
</tr>
<tr class="row-odd"><td>Windows</td>
<td>cmd.exe</td>
<td>C:\> <venv>\Scripts\activate.bat</td>
</tr>
<tr class="row-even"><td> </td>
<td>PowerShell</td>
<td>PS C:\> <venv>\Scripts\Activate.ps1</td>
</tr>
</tbody>
</table>
<p>You don’t specifically <em>need</em> to activate an environment; activation just
prepends the venv’s binary directory to your path, so that “python” invokes the
venv’s Python interpreter and you can run installed scripts without having to
use their full path. However, all scripts installed in a venv should be
runnable without activating it, and run with the venv’s Python automatically.</p>
<p>You can deactivate a venv by typing “deactivate” in your shell. The exact
mechanism is platform-specific: for example, the Bash activation script defines
a “deactivate” function, whereas on Windows there are separate scripts called
<code class="docutils literal notranslate"><span class="pre">deactivate.bat</span></code> and <code class="docutils literal notranslate"><span class="pre">Deactivate.ps1</span></code> which are installed when the venv is
created.</p>
<div class="versionadded">
<p><span class="versionmodified">New in version 3.4: </span><code class="docutils literal notranslate"><span class="pre">fish</span></code> and <code class="docutils literal notranslate"><span class="pre">csh</span></code> activation scripts.</p>
</div>
<div class="admonition note" id="venv-def">
<p class="first admonition-title">Note</p>
<p>A virtual environment (also called a <code class="docutils literal notranslate"><span class="pre">venv</span></code>) is a Python
environment such that the Python interpreter, libraries and scripts
installed into it are isolated from those installed in other virtual
environments, and (by default) any libraries installed in a “system” Python,
i.e. one which is installed as part of your operating system.</p>
<p>A venv is a directory tree which contains Python executable files and
other files which indicate that it is a venv.</p>
<p>Common installation tools such as <code class="docutils literal notranslate"><span class="pre">Setuptools</span></code> and <code class="docutils literal notranslate"><span class="pre">pip</span></code> work as
expected with venvs - i.e. when a venv is active, they install Python
packages into the venv without needing to be told to do so explicitly.</p>
<p>When a venv is active (i.e. the venv’s Python interpreter is running), the
attributes <a class="reference internal" href="sys.html#sys.prefix" title="sys.prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.prefix</span></code></a> and <a class="reference internal" href="sys.html#sys.exec_prefix" title="sys.exec_prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.exec_prefix</span></code></a> point to the base
directory of the venv, whereas <a class="reference internal" href="sys.html#sys.base_prefix" title="sys.base_prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.base_prefix</span></code></a> and
<a class="reference internal" href="sys.html#sys.base_exec_prefix" title="sys.base_exec_prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.base_exec_prefix</span></code></a> point to the non-venv Python installation
which was used to create the venv. If a venv is not active, then
<a class="reference internal" href="sys.html#sys.prefix" title="sys.prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.prefix</span></code></a> is the same as <a class="reference internal" href="sys.html#sys.base_prefix" title="sys.base_prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.base_prefix</span></code></a> and
<a class="reference internal" href="sys.html#sys.exec_prefix" title="sys.exec_prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.exec_prefix</span></code></a> is the same as <a class="reference internal" href="sys.html#sys.base_exec_prefix" title="sys.base_exec_prefix"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.base_exec_prefix</span></code></a> (they
all point to a non-venv Python installation).</p>
<p>When a venv is active, any options that change the installation path will be
ignored from all distutils configuration files to prevent projects being
inadvertently installed outside of the virtual environment.</p>
<p class="last">When working in a command shell, users can make a venv active by running an
<code class="docutils literal notranslate"><span class="pre">activate</span></code> script in the venv’s executables directory (the precise filename
is shell-dependent), which prepends the venv’s directory for executables to
the <code class="docutils literal notranslate"><span class="pre">PATH</span></code> environment variable for the running shell. There should be no
need in other circumstances to activate a venv – scripts installed into
venvs have a shebang line which points to the venv’s Python interpreter. This
means that the script will run with that interpreter regardless of the value
of <code class="docutils literal notranslate"><span class="pre">PATH</span></code>. On Windows, shebang line processing is supported if you have the
Python Launcher for Windows installed (this was added to Python in 3.3 - see
<span class="target" id="index-2"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0397"><strong>PEP 397</strong></a> for more details). Thus, double-clicking an installed script in
a Windows Explorer window should run the script with the correct interpreter
without there needing to be any reference to its venv in <code class="docutils literal notranslate"><span class="pre">PATH</span></code>.</p>
</div>
</div>
<div class="section" id="api">
<span id="venv-api"></span><h2>28.3.2. API<a class="headerlink" href="#api" title="Permalink to this headline">¶</a></h2>
<p>The high-level method described above makes use of a simple API which provides
mechanisms for third-party virtual environment creators to customize environment
creation according to their needs, the <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> class.</p>
<dl class="class">
<dt id="venv.EnvBuilder">
<em class="property">class </em><code class="descclassname">venv.</code><code class="descname">EnvBuilder</code><span class="sig-paren">(</span><em>system_site_packages=False</em>, <em>clear=False</em>, <em>symlinks=False</em>, <em>upgrade=False</em>, <em>with_pip=False</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder" title="Permalink to this definition">¶</a></dt>
<dd><p>The <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> class accepts the following keyword arguments on
instantiation:</p>
<ul class="simple">
<li><code class="docutils literal notranslate"><span class="pre">system_site_packages</span></code> – a Boolean value indicating that the system Python
site-packages should be available to the environment (defaults to <code class="docutils literal notranslate"><span class="pre">False</span></code>).</li>
<li><code class="docutils literal notranslate"><span class="pre">clear</span></code> – a Boolean value which, if true, will delete the contents of
any existing target directory, before creating the environment.</li>
<li><code class="docutils literal notranslate"><span class="pre">symlinks</span></code> – a Boolean value indicating whether to attempt to symlink the
Python binary (and any necessary DLLs or other binaries,
e.g. <code class="docutils literal notranslate"><span class="pre">pythonw.exe</span></code>), rather than copying. Defaults to <code class="docutils literal notranslate"><span class="pre">True</span></code> on Linux and
Unix systems, but <code class="docutils literal notranslate"><span class="pre">False</span></code> on Windows.</li>
<li><code class="docutils literal notranslate"><span class="pre">upgrade</span></code> – a Boolean value which, if true, will upgrade an existing
environment with the running Python - for use when that Python has been
upgraded in-place (defaults to <code class="docutils literal notranslate"><span class="pre">False</span></code>).</li>
<li><code class="docutils literal notranslate"><span class="pre">with_pip</span></code> – a Boolean value which, if true, ensures pip is
installed in the virtual environment. This uses <a class="reference internal" href="ensurepip.html#module-ensurepip" title="ensurepip: Bootstrapping the "pip" installer into an existing Python installation or virtual environment."><code class="xref py py-mod docutils literal notranslate"><span class="pre">ensurepip</span></code></a> with
the <code class="docutils literal notranslate"><span class="pre">--default-pip</span></code> option.</li>
</ul>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>Added the <code class="docutils literal notranslate"><span class="pre">with_pip</span></code> parameter</p>
</div>
<p>Creators of third-party virtual environment tools will be free to use the
provided <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code> class as a base class.</p>
<p>The returned env-builder is an object which has a method, <code class="docutils literal notranslate"><span class="pre">create</span></code>:</p>
<dl class="method">
<dt id="venv.EnvBuilder.create">
<code class="descname">create</code><span class="sig-paren">(</span><em>env_dir</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.create" title="Permalink to this definition">¶</a></dt>
<dd><p>This method takes as required argument the path (absolute or relative to
the current directory) of the target directory which is to contain the
virtual environment. The <code class="docutils literal notranslate"><span class="pre">create</span></code> method will either create the
environment in the specified directory, or raise an appropriate
exception.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">create</span></code> method of the <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code> class illustrates the hooks
available for subclass customization:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">create</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">env_dir</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Create a virtualized Python environment in a directory.</span>
<span class="sd"> env_dir is the target directory to create an environment in.</span>
<span class="sd"> """</span>
<span class="n">env_dir</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">abspath</span><span class="p">(</span><span class="n">env_dir</span><span class="p">)</span>
<span class="n">context</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">ensure_directories</span><span class="p">(</span><span class="n">env_dir</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">create_configuration</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">setup_python</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">setup_scripts</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">post_setup</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>
</pre></div>
</div>
<p>Each of the methods <a class="reference internal" href="#venv.EnvBuilder.ensure_directories" title="venv.EnvBuilder.ensure_directories"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ensure_directories()</span></code></a>,
<a class="reference internal" href="#venv.EnvBuilder.create_configuration" title="venv.EnvBuilder.create_configuration"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_configuration()</span></code></a>, <a class="reference internal" href="#venv.EnvBuilder.setup_python" title="venv.EnvBuilder.setup_python"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_python()</span></code></a>,
<a class="reference internal" href="#venv.EnvBuilder.setup_scripts" title="venv.EnvBuilder.setup_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_scripts()</span></code></a> and <a class="reference internal" href="#venv.EnvBuilder.post_setup" title="venv.EnvBuilder.post_setup"><code class="xref py py-meth docutils literal notranslate"><span class="pre">post_setup()</span></code></a> can be overridden.</p>
</dd></dl>
<dl class="method">
<dt id="venv.EnvBuilder.ensure_directories">
<code class="descname">ensure_directories</code><span class="sig-paren">(</span><em>env_dir</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.ensure_directories" title="Permalink to this definition">¶</a></dt>
<dd><p>Creates the environment directory and all necessary directories, and
returns a context object. This is just a holder for attributes (such as
paths), for use by the other methods. The directories are allowed to
exist already, as long as either <code class="docutils literal notranslate"><span class="pre">clear</span></code> or <code class="docutils literal notranslate"><span class="pre">upgrade</span></code> were
specified to allow operating on an existing environment directory.</p>
</dd></dl>
<dl class="method">
<dt id="venv.EnvBuilder.create_configuration">
<code class="descname">create_configuration</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.create_configuration" title="Permalink to this definition">¶</a></dt>
<dd><p>Creates the <code class="docutils literal notranslate"><span class="pre">pyvenv.cfg</span></code> configuration file in the environment.</p>
</dd></dl>
<dl class="method">
<dt id="venv.EnvBuilder.setup_python">
<code class="descname">setup_python</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.setup_python" title="Permalink to this definition">¶</a></dt>
<dd><p>Creates a copy of the Python executable (and, under Windows, DLLs) in
the environment. On a POSIX system, if a specific executable
<code class="docutils literal notranslate"><span class="pre">python3.x</span></code> was used, symlinks to <code class="docutils literal notranslate"><span class="pre">python</span></code> and <code class="docutils literal notranslate"><span class="pre">python3</span></code> will be
created pointing to that executable, unless files with those names
already exist.</p>
</dd></dl>
<dl class="method">
<dt id="venv.EnvBuilder.setup_scripts">
<code class="descname">setup_scripts</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.setup_scripts" title="Permalink to this definition">¶</a></dt>
<dd><p>Installs activation scripts appropriate to the platform into the virtual
environment.</p>
</dd></dl>
<dl class="method">
<dt id="venv.EnvBuilder.post_setup">
<code class="descname">post_setup</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.post_setup" title="Permalink to this definition">¶</a></dt>
<dd><p>A placeholder method which can be overridden in third party
implementations to pre-install packages in the virtual environment or
perform other post-creation steps.</p>
</dd></dl>
<p>In addition, <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> provides this utility method that can be
called from <a class="reference internal" href="#venv.EnvBuilder.setup_scripts" title="venv.EnvBuilder.setup_scripts"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setup_scripts()</span></code></a> or <a class="reference internal" href="#venv.EnvBuilder.post_setup" title="venv.EnvBuilder.post_setup"><code class="xref py py-meth docutils literal notranslate"><span class="pre">post_setup()</span></code></a> in subclasses to
assist in installing custom scripts into the virtual environment.</p>
<dl class="method">
<dt id="venv.EnvBuilder.install_scripts">
<code class="descname">install_scripts</code><span class="sig-paren">(</span><em>context</em>, <em>path</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.EnvBuilder.install_scripts" title="Permalink to this definition">¶</a></dt>
<dd><p><em>path</em> is the path to a directory that should contain subdirectories
“common”, “posix”, “nt”, each containing scripts destined for the bin
directory in the environment. The contents of “common” and the
directory corresponding to <a class="reference internal" href="os.html#os.name" title="os.name"><code class="xref py py-data docutils literal notranslate"><span class="pre">os.name</span></code></a> are copied after some text
replacement of placeholders:</p>
<ul class="simple">
<li><code class="docutils literal notranslate"><span class="pre">__VENV_DIR__</span></code> is replaced with the absolute path of the environment
directory.</li>
<li><code class="docutils literal notranslate"><span class="pre">__VENV_NAME__</span></code> is replaced with the environment name (final path
segment of environment directory).</li>
<li><code class="docutils literal notranslate"><span class="pre">__VENV_PROMPT__</span></code> is replaced with the prompt (the environment
name surrounded by parentheses and with a following space)</li>
<li><code class="docutils literal notranslate"><span class="pre">__VENV_BIN_NAME__</span></code> is replaced with the name of the bin directory
(either <code class="docutils literal notranslate"><span class="pre">bin</span></code> or <code class="docutils literal notranslate"><span class="pre">Scripts</span></code>).</li>
<li><code class="docutils literal notranslate"><span class="pre">__VENV_PYTHON__</span></code> is replaced with the absolute path of the
environment’s executable.</li>
</ul>
<p>The directories are allowed to exist (for when an existing environment
is being upgraded).</p>
</dd></dl>
</dd></dl>
<p>There is also a module-level convenience function:</p>
<dl class="function">
<dt id="venv.create">
<code class="descclassname">venv.</code><code class="descname">create</code><span class="sig-paren">(</span><em>env_dir</em>, <em>system_site_packages=False</em>, <em>clear=False</em>, <em>symlinks=False</em>, <em>with_pip=False</em><span class="sig-paren">)</span><a class="headerlink" href="#venv.create" title="Permalink to this definition">¶</a></dt>
<dd><p>Create an <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> with the given keyword arguments, and call its
<a class="reference internal" href="#venv.EnvBuilder.create" title="venv.EnvBuilder.create"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create()</span></code></a> method with the <em>env_dir</em> argument.</p>
<div class="versionchanged">
<p><span class="versionmodified">Changed in version 3.4: </span>Added the <code class="docutils literal notranslate"><span class="pre">with_pip</span></code> parameter</p>
</div>
</dd></dl>
</div>
<div class="section" id="an-example-of-extending-envbuilder">
<h2>28.3.3. An example of extending <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code><a class="headerlink" href="#an-example-of-extending-envbuilder" title="Permalink to this headline">¶</a></h2>
<p>The following script shows how to extend <a class="reference internal" href="#venv.EnvBuilder" title="venv.EnvBuilder"><code class="xref py py-class docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a> by implementing a
subclass which installs setuptools and pip into a created venv:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">os</span>
<span class="kn">import</span> <span class="nn">os.path</span>
<span class="kn">from</span> <span class="nn">subprocess</span> <span class="kn">import</span> <span class="n">Popen</span><span class="p">,</span> <span class="n">PIPE</span>
<span class="kn">import</span> <span class="nn">sys</span>
<span class="kn">from</span> <span class="nn">threading</span> <span class="kn">import</span> <span class="n">Thread</span>
<span class="kn">from</span> <span class="nn">urllib.parse</span> <span class="kn">import</span> <span class="n">urlparse</span>
<span class="kn">from</span> <span class="nn">urllib.request</span> <span class="kn">import</span> <span class="n">urlretrieve</span>
<span class="kn">import</span> <span class="nn">venv</span>
<span class="k">class</span> <span class="nc">ExtendedEnvBuilder</span><span class="p">(</span><span class="n">venv</span><span class="o">.</span><span class="n">EnvBuilder</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> This builder installs setuptools and pip so that you can pip or</span>
<span class="sd"> easy_install other packages into the created environment.</span>
<span class="sd"> :param nodist: If True, setuptools and pip are not installed into the</span>
<span class="sd"> created environment.</span>
<span class="sd"> :param nopip: If True, pip is not installed into the created</span>
<span class="sd"> environment.</span>
<span class="sd"> :param progress: If setuptools or pip are installed, the progress of the</span>
<span class="sd"> installation can be monitored by passing a progress</span>
<span class="sd"> callable. If specified, it is called with two</span>
<span class="sd"> arguments: a string indicating some progress, and a</span>
<span class="sd"> context indicating where the string is coming from.</span>
<span class="sd"> The context argument can have one of three values:</span>
<span class="sd"> 'main', indicating that it is called from virtualize()</span>
<span class="sd"> itself, and 'stdout' and 'stderr', which are obtained</span>
<span class="sd"> by reading lines from the output streams of a subprocess</span>
<span class="sd"> which is used to install the app.</span>
<span class="sd"> If a callable is not specified, default progress</span>
<span class="sd"> information is output to sys.stderr.</span>
<span class="sd"> """</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">nodist</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'nodist'</span><span class="p">,</span> <span class="bp">False</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">nopip</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'nopip'</span><span class="p">,</span> <span class="bp">False</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">progress</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'progress'</span><span class="p">,</span> <span class="bp">None</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">verbose</span> <span class="o">=</span> <span class="n">kwargs</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="s1">'verbose'</span><span class="p">,</span> <span class="bp">False</span><span class="p">)</span>
<span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="fm">__init__</span><span class="p">(</span><span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">post_setup</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Set up any packages which need to be pre-installed into the</span>
<span class="sd"> environment being created.</span>
<span class="sd"> :param context: The information for the environment creation request</span>
<span class="sd"> being processed.</span>
<span class="sd"> """</span>
<span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s1">'VIRTUAL_ENV'</span><span class="p">]</span> <span class="o">=</span> <span class="n">context</span><span class="o">.</span><span class="n">env_dir</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">nodist</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">install_setuptools</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>
<span class="c1"># Can't install pip without setuptools</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">nopip</span> <span class="ow">and</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">nodist</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">install_pip</span><span class="p">(</span><span class="n">context</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">reader</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">stream</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Read lines from a subprocess' output stream and either pass to a progress</span>
<span class="sd"> callable (if specified) or write progress information to sys.stderr.</span>
<span class="sd"> """</span>
<span class="n">progress</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">progress</span>
<span class="k">while</span> <span class="bp">True</span><span class="p">:</span>
<span class="n">s</span> <span class="o">=</span> <span class="n">stream</span><span class="o">.</span><span class="n">readline</span><span class="p">()</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">s</span><span class="p">:</span>
<span class="k">break</span>
<span class="k">if</span> <span class="n">progress</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span><span class="p">:</span>
<span class="n">progress</span><span class="p">(</span><span class="n">s</span><span class="p">,</span> <span class="n">context</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">verbose</span><span class="p">:</span>
<span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'.'</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">s</span><span class="o">.</span><span class="n">decode</span><span class="p">(</span><span class="s1">'utf-8'</span><span class="p">))</span>
<span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">flush</span><span class="p">()</span>
<span class="n">stream</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">install_script</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">,</span> <span class="n">name</span><span class="p">,</span> <span class="n">url</span><span class="p">):</span>
<span class="n">_</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">path</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">_</span> <span class="o">=</span> <span class="n">urlparse</span><span class="p">(</span><span class="n">url</span><span class="p">)</span>
<span class="n">fn</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">split</span><span class="p">(</span><span class="n">path</span><span class="p">)[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<span class="n">binpath</span> <span class="o">=</span> <span class="n">context</span><span class="o">.</span><span class="n">bin_path</span>
<span class="n">distpath</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">binpath</span><span class="p">,</span> <span class="n">fn</span><span class="p">)</span>
<span class="c1"># Download script into the env's binaries folder</span>
<span class="n">urlretrieve</span><span class="p">(</span><span class="n">url</span><span class="p">,</span> <span class="n">distpath</span><span class="p">)</span>
<span class="n">progress</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">progress</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">verbose</span><span class="p">:</span>
<span class="n">term</span> <span class="o">=</span> <span class="s1">'</span><span class="se">\n</span><span class="s1">'</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">term</span> <span class="o">=</span> <span class="s1">''</span>
<span class="k">if</span> <span class="n">progress</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span><span class="p">:</span>
<span class="n">progress</span><span class="p">(</span><span class="s1">'Installing </span><span class="si">%s</span><span class="s1"> ...</span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">term</span><span class="p">),</span> <span class="s1">'main'</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'Installing </span><span class="si">%s</span><span class="s1"> ...</span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">term</span><span class="p">))</span>
<span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">flush</span><span class="p">()</span>
<span class="c1"># Install in the env</span>
<span class="n">args</span> <span class="o">=</span> <span class="p">[</span><span class="n">context</span><span class="o">.</span><span class="n">env_exe</span><span class="p">,</span> <span class="n">fn</span><span class="p">]</span>
<span class="n">p</span> <span class="o">=</span> <span class="n">Popen</span><span class="p">(</span><span class="n">args</span><span class="p">,</span> <span class="n">stdout</span><span class="o">=</span><span class="n">PIPE</span><span class="p">,</span> <span class="n">stderr</span><span class="o">=</span><span class="n">PIPE</span><span class="p">,</span> <span class="n">cwd</span><span class="o">=</span><span class="n">binpath</span><span class="p">)</span>
<span class="n">t1</span> <span class="o">=</span> <span class="n">Thread</span><span class="p">(</span><span class="n">target</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reader</span><span class="p">,</span> <span class="n">args</span><span class="o">=</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">stdout</span><span class="p">,</span> <span class="s1">'stdout'</span><span class="p">))</span>
<span class="n">t1</span><span class="o">.</span><span class="n">start</span><span class="p">()</span>
<span class="n">t2</span> <span class="o">=</span> <span class="n">Thread</span><span class="p">(</span><span class="n">target</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reader</span><span class="p">,</span> <span class="n">args</span><span class="o">=</span><span class="p">(</span><span class="n">p</span><span class="o">.</span><span class="n">stderr</span><span class="p">,</span> <span class="s1">'stderr'</span><span class="p">))</span>
<span class="n">t2</span><span class="o">.</span><span class="n">start</span><span class="p">()</span>
<span class="n">p</span><span class="o">.</span><span class="n">wait</span><span class="p">()</span>
<span class="n">t1</span><span class="o">.</span><span class="n">join</span><span class="p">()</span>
<span class="n">t2</span><span class="o">.</span><span class="n">join</span><span class="p">()</span>
<span class="k">if</span> <span class="n">progress</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span><span class="p">:</span>
<span class="n">progress</span><span class="p">(</span><span class="s1">'done.'</span><span class="p">,</span> <span class="s1">'main'</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'done.</span><span class="se">\n</span><span class="s1">'</span><span class="p">)</span>
<span class="c1"># Clean up - no longer needed</span>
<span class="n">os</span><span class="o">.</span><span class="n">unlink</span><span class="p">(</span><span class="n">distpath</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">install_setuptools</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Install setuptools in the environment.</span>
<span class="sd"> :param context: The information for the environment creation request</span>
<span class="sd"> being processed.</span>
<span class="sd"> """</span>
<span class="n">url</span> <span class="o">=</span> <span class="s1">'https://bitbucket.org/pypa/setuptools/downloads/ez_setup.py'</span>
<span class="bp">self</span><span class="o">.</span><span class="n">install_script</span><span class="p">(</span><span class="n">context</span><span class="p">,</span> <span class="s1">'setuptools'</span><span class="p">,</span> <span class="n">url</span><span class="p">)</span>
<span class="c1"># clear up the setuptools archive which gets downloaded</span>
<span class="n">pred</span> <span class="o">=</span> <span class="k">lambda</span> <span class="n">o</span><span class="p">:</span> <span class="n">o</span><span class="o">.</span><span class="n">startswith</span><span class="p">(</span><span class="s1">'setuptools-'</span><span class="p">)</span> <span class="ow">and</span> <span class="n">o</span><span class="o">.</span><span class="n">endswith</span><span class="p">(</span><span class="s1">'.tar.gz'</span><span class="p">)</span>
<span class="n">files</span> <span class="o">=</span> <span class="nb">filter</span><span class="p">(</span><span class="n">pred</span><span class="p">,</span> <span class="n">os</span><span class="o">.</span><span class="n">listdir</span><span class="p">(</span><span class="n">context</span><span class="o">.</span><span class="n">bin_path</span><span class="p">))</span>
<span class="k">for</span> <span class="n">f</span> <span class="ow">in</span> <span class="n">files</span><span class="p">:</span>
<span class="n">f</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">context</span><span class="o">.</span><span class="n">bin_path</span><span class="p">,</span> <span class="n">f</span><span class="p">)</span>
<span class="n">os</span><span class="o">.</span><span class="n">unlink</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">install_pip</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">context</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Install pip in the environment.</span>
<span class="sd"> :param context: The information for the environment creation request</span>
<span class="sd"> being processed.</span>
<span class="sd"> """</span>
<span class="n">url</span> <span class="o">=</span> <span class="s1">'https://raw.github.com/pypa/pip/master/contrib/get-pip.py'</span>
<span class="bp">self</span><span class="o">.</span><span class="n">install_script</span><span class="p">(</span><span class="n">context</span><span class="p">,</span> <span class="s1">'pip'</span><span class="p">,</span> <span class="n">url</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">main</span><span class="p">(</span><span class="n">args</span><span class="o">=</span><span class="bp">None</span><span class="p">):</span>
<span class="n">compatible</span> <span class="o">=</span> <span class="bp">True</span>
<span class="k">if</span> <span class="n">sys</span><span class="o">.</span><span class="n">version_info</span> <span class="o"><</span> <span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="mi">3</span><span class="p">):</span>
<span class="n">compatible</span> <span class="o">=</span> <span class="bp">False</span>
<span class="k">elif</span> <span class="ow">not</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">sys</span><span class="p">,</span> <span class="s1">'base_prefix'</span><span class="p">):</span>
<span class="n">compatible</span> <span class="o">=</span> <span class="bp">False</span>
<span class="k">if</span> <span class="ow">not</span> <span class="n">compatible</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">'This script is only for use with '</span>
<span class="s1">'Python 3.3 or later'</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="kn">import</span> <span class="nn">argparse</span>
<span class="n">parser</span> <span class="o">=</span> <span class="n">argparse</span><span class="o">.</span><span class="n">ArgumentParser</span><span class="p">(</span><span class="n">prog</span><span class="o">=</span><span class="vm">__name__</span><span class="p">,</span>
<span class="n">description</span><span class="o">=</span><span class="s1">'Creates virtual Python '</span>
<span class="s1">'environments in one or '</span>
<span class="s1">'more target '</span>
<span class="s1">'directories.'</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'dirs'</span><span class="p">,</span> <span class="n">metavar</span><span class="o">=</span><span class="s1">'ENV_DIR'</span><span class="p">,</span> <span class="n">nargs</span><span class="o">=</span><span class="s1">'+'</span><span class="p">,</span>
<span class="n">help</span><span class="o">=</span><span class="s1">'A directory to create the environment in.'</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--no-setuptools'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span>
<span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">'nodist'</span><span class="p">,</span>
<span class="n">help</span><span class="o">=</span><span class="s2">"Don't install setuptools or pip in the "</span>
<span class="s2">"virtual environment."</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--no-pip'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span>
<span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">'nopip'</span><span class="p">,</span>
<span class="n">help</span><span class="o">=</span><span class="s2">"Don't install pip in the virtual "</span>
<span class="s2">"environment."</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--system-site-packages'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span>
<span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">'system_site'</span><span class="p">,</span>
<span class="n">help</span><span class="o">=</span><span class="s1">'Give the virtual environment access to the '</span>
<span class="s1">'system site-packages dir.'</span><span class="p">)</span>
<span class="k">if</span> <span class="n">os</span><span class="o">.</span><span class="n">name</span> <span class="o">==</span> <span class="s1">'nt'</span><span class="p">:</span>
<span class="n">use_symlinks</span> <span class="o">=</span> <span class="bp">False</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">use_symlinks</span> <span class="o">=</span> <span class="bp">True</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--symlinks'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="n">use_symlinks</span><span class="p">,</span>
<span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span> <span class="n">dest</span><span class="o">=</span><span class="s1">'symlinks'</span><span class="p">,</span>
<span class="n">help</span><span class="o">=</span><span class="s1">'Try to use symlinks rather than copies, '</span>
<span class="s1">'when symlinks are not the default for '</span>
<span class="s1">'the platform.'</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--clear'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span>
<span class="n">dest</span><span class="o">=</span><span class="s1">'clear'</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s1">'Delete the contents of the '</span>
<span class="s1">'environment directory if it '</span>
<span class="s1">'already exists, before '</span>
<span class="s1">'environment creation.'</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--upgrade'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span>
<span class="n">dest</span><span class="o">=</span><span class="s1">'upgrade'</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s1">'Upgrade the environment '</span>
<span class="s1">'directory to use this version '</span>
<span class="s1">'of Python, assuming Python '</span>
<span class="s1">'has been upgraded in-place.'</span><span class="p">)</span>
<span class="n">parser</span><span class="o">.</span><span class="n">add_argument</span><span class="p">(</span><span class="s1">'--verbose'</span><span class="p">,</span> <span class="n">default</span><span class="o">=</span><span class="bp">False</span><span class="p">,</span> <span class="n">action</span><span class="o">=</span><span class="s1">'store_true'</span><span class="p">,</span>
<span class="n">dest</span><span class="o">=</span><span class="s1">'verbose'</span><span class="p">,</span> <span class="n">help</span><span class="o">=</span><span class="s1">'Display the output '</span>
<span class="s1">'from the scripts which '</span>
<span class="s1">'install setuptools and pip.'</span><span class="p">)</span>
<span class="n">options</span> <span class="o">=</span> <span class="n">parser</span><span class="o">.</span><span class="n">parse_args</span><span class="p">(</span><span class="n">args</span><span class="p">)</span>
<span class="k">if</span> <span class="n">options</span><span class="o">.</span><span class="n">upgrade</span> <span class="ow">and</span> <span class="n">options</span><span class="o">.</span><span class="n">clear</span><span class="p">:</span>
<span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s1">'you cannot supply --upgrade and --clear together.'</span><span class="p">)</span>
<span class="n">builder</span> <span class="o">=</span> <span class="n">ExtendedEnvBuilder</span><span class="p">(</span><span class="n">system_site_packages</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">system_site</span><span class="p">,</span>
<span class="n">clear</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">clear</span><span class="p">,</span>
<span class="n">symlinks</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">symlinks</span><span class="p">,</span>
<span class="n">upgrade</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">upgrade</span><span class="p">,</span>
<span class="n">nodist</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">nodist</span><span class="p">,</span>
<span class="n">nopip</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">nopip</span><span class="p">,</span>
<span class="n">verbose</span><span class="o">=</span><span class="n">options</span><span class="o">.</span><span class="n">verbose</span><span class="p">)</span>
<span class="k">for</span> <span class="n">d</span> <span class="ow">in</span> <span class="n">options</span><span class="o">.</span><span class="n">dirs</span><span class="p">:</span>
<span class="n">builder</span><span class="o">.</span><span class="n">create</span><span class="p">(</span><span class="n">d</span><span class="p">)</span>
<span class="k">if</span> <span class="vm">__name__</span> <span class="o">==</span> <span class="s1">'__main__'</span><span class="p">:</span>
<span class="n">rc</span> <span class="o">=</span> <span class="mi">1</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">main</span><span class="p">()</span>
<span class="n">rc</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">except</span> <span class="ne">Exception</span> <span class="k">as</span> <span class="n">e</span><span class="p">:</span>
<span class="k">print</span><span class="p">(</span><span class="s1">'Error: </span><span class="si">%s</span><span class="s1">'</span> <span class="o">%</span> <span class="n">e</span><span class="p">,</span> <span class="nb">file</span><span class="o">=</span><span class="n">sys</span><span class="o">.</span><span class="n">stderr</span><span class="p">)</span>
<span class="n">sys</span><span class="o">.</span><span class="n">exit</span><span class="p">(</span><span class="n">rc</span><span class="p">)</span>
</pre></div>
</div>
<p>This script is also available for download <a class="reference external" href="https://gist.github.com/4673395">online</a>.</p>
</div>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar" role="navigation" aria-label="main navigation">
<div class="sphinxsidebarwrapper">
<h3><a href="../contents.html">Table of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">28.3. <code class="docutils literal notranslate"><span class="pre">venv</span></code> — Creation of virtual environments</a><ul>
<li><a class="reference internal" href="#creating-virtual-environments">28.3.1. Creating virtual environments</a></li>
<li><a class="reference internal" href="#api">28.3.2. API</a></li>
<li><a class="reference internal" href="#an-example-of-extending-envbuilder">28.3.3. An example of extending <code class="docutils literal notranslate"><span class="pre">EnvBuilder</span></code></a></li>
</ul>
</li>
</ul>
<h4>Previous topic</h4>
<p class="topless"><a href="ensurepip.html"
title="previous chapter">28.2. <code class="docutils literal notranslate"><span class="pre">ensurepip</span></code> — Bootstrapping the <code class="docutils literal notranslate"><span class="pre">pip</span></code> installer</a></p>
<h4>Next topic</h4>
<p class="topless"><a href="zipapp.html"
title="next chapter">28.4. <code class="docutils literal notranslate"><span class="pre">zipapp</span></code> — Manage executable python zip archives</a></p>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../bugs.html">Report a Bug</a></li>
<li>
<a href="https://github.com/python/cpython/blob/3.5/Doc/library/venv.rst"
rel="nofollow">Show Source
</a>
</li>
</ul>
</div>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../genindex.html" title="General Index"
>index</a></li>
<li class="right" >
<a href="../py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="zipapp.html" title="28.4. zipapp — Manage executable python zip archives"
>next</a> |</li>
<li class="right" >
<a href="ensurepip.html" title="28.2. ensurepip — Bootstrapping the pip installer"
>previous</a> |</li>
<li><img src="../_static/py.png" alt=""
style="vertical-align: middle; margin-top: -1px"/></li>
<li><a href="https://www.python.org/">Python</a> »</li>
<li>
<a href="../index.html">3.5.7 Documentation</a> »
</li>
<li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li>
<li class="nav-item nav-item-2"><a href="distribution.html" >28. Software Packaging and Distribution</a> »</li>
<li class="right">
<div class="inline-search" style="display: none" role="search">
<form class="inline-search" action="../search.html" method="get">
<input placeholder="Quick search" type="text" name="q" />
<input type="submit" value="Go" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
<script type="text/javascript">$('.inline-search').show(0);</script>
|
</li>
</ul>
</div>
<div class="footer">
© <a href="../copyright.html">Copyright</a> 2001-2019, Python Software Foundation.
<br />
The Python Software Foundation is a non-profit corporation.
<a href="https://www.python.org/psf/donations/">Please donate.</a>
<br />
Last updated on Mar 17, 2019.
<a href="../bugs.html">Found a bug</a>?
<br />
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.8.4.
</div>
</body>
</html>
distrib
>
Mageia
>
6
>
x86_64
>
media
>
core-updates
>
by-pkgid
>
cc36b290822e608658341b1bb9421f39
>
files
>
943
