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class="breadcrumbs"> <li><a href="https://www.python.org/" title="The Python Programming Language">Python</a> » </li> <li><a href="../pep-0000/">PEP Index</a> » </li> <li>PEP 394</li> </ul> <button id="colour-scheme-cycler" onClick="setColourScheme(nextColourScheme())"> <svg aria-hidden="true" class="colour-scheme-icon-when-auto"><use href="#svg-sun-half"></use></svg> <svg aria-hidden="true" class="colour-scheme-icon-when-dark"><use href="#svg-moon"></use></svg> <svg aria-hidden="true" class="colour-scheme-icon-when-light"><use href="#svg-sun"></use></svg> <span class="visually-hidden">Toggle light / dark / auto colour theme</span> </button> </header> <article> <section id="pep-content"> <h1 class="page-title">PEP 394 – The “python” Command on Unix-Like Systems</h1> <dl class="rfc2822 field-list simple"> <dt class="field-odd">Author<span class="colon">:</span></dt> <dd class="field-odd">Kerrick Staley <mail at kerrickstaley.com>, Alyssa Coghlan <ncoghlan at gmail.com>, Barry Warsaw <barry at python.org>, Petr Viktorin <encukou at gmail.com>, Miro Hrončok <miro at hroncok.cz>, Carol Willing <willingc at gmail.com></dd> <dt class="field-even">Status<span class="colon">:</span></dt> <dd class="field-even"><abbr title="Currently valid informational guidance, or an in-use process">Active</abbr></dd> <dt class="field-odd">Type<span class="colon">:</span></dt> <dd class="field-odd"><abbr title="Non-normative PEP containing background, guidelines or other information relevant to the Python ecosystem">Informational</abbr></dd> <dt class="field-even">Created<span class="colon">:</span></dt> <dd class="field-even">02-Mar-2011</dd> <dt class="field-odd">Post-History<span class="colon">:</span></dt> <dd class="field-odd">04-Mar-2011, 20-Jul-2011, 16-Feb-2012, 30-Sep-2014, 28-Apr-2018, 26-Jun-2019</dd> <dt class="field-even">Resolution<span class="colon">:</span></dt> <dd class="field-even"><a class="reference external" href="https://mail.python.org/pipermail/python-dev/2012-February/116594.html">Python-Dev message</a></dd> </dl> <hr class="docutils" /> <section id="contents"> <details><summary>Table of Contents</summary><ul class="simple"> <li><a class="reference internal" href="#abstract">Abstract</a></li> <li><a class="reference internal" href="#recommendation">Recommendation</a><ul> <li><a class="reference internal" href="#for-python-runtime-distributors">For Python runtime distributors</a></li> <li><a class="reference internal" href="#for-python-script-publishers">For Python script publishers</a></li> <li><a class="reference internal" href="#for-end-users-of-python">For end users of Python</a></li> </ul> </li> <li><a class="reference internal" href="#history-of-this-pep">History of this PEP</a></li> <li><a class="reference internal" href="#current-rationale">Current Rationale</a></li> <li><a class="reference internal" href="#future-changes-to-this-recommendation">Future Changes to this Recommendation</a></li> <li><a class="reference internal" href="#migration-notes">Migration Notes</a></li> <li><a class="reference internal" href="#backwards-compatibility">Backwards Compatibility</a></li> <li><a class="reference internal" href="#application-to-the-cpython-reference-interpreter">Application to the CPython Reference Interpreter</a></li> <li><a class="reference internal" href="#impact-on-python-environment-variables">Impact on PYTHON* Environment Variables</a></li> <li><a class="reference internal" href="#exclusion-of-ms-windows">Exclusion of MS Windows</a></li> <li><a class="reference internal" href="#references">References</a></li> <li><a class="reference internal" href="#copyright">Copyright</a></li> </ul> </details></section> <section id="abstract"> <h2><a class="toc-backref" href="#abstract" role="doc-backlink">Abstract</a></h2> <p>This PEP outlines the behavior of Python scripts when the <code class="docutils literal notranslate"><span class="pre">python</span></code> command is invoked. Depending on a distribution or system configuration, <code class="docutils literal notranslate"><span class="pre">python</span></code> may or may not be installed. If <code class="docutils literal notranslate"><span class="pre">python</span></code> is installed its target interpreter may refer to <code class="docutils literal notranslate"><span class="pre">python2</span></code> or <code class="docutils literal notranslate"><span class="pre">python3</span></code>. End users may be unaware of this inconsistency across Unix-like systems. This PEP’s goal is to reduce user confusion about what <code class="docutils literal notranslate"><span class="pre">python</span></code> references and what will be the script’s behavior.</p> <p>The recommendations in the next section of this PEP will outline the behavior when:</p> <ul class="simple"> <li>using virtual environments</li> <li>writing cross-platform scripts with shebangs for either <code class="docutils literal notranslate"><span class="pre">python2</span></code> or <code class="docutils literal notranslate"><span class="pre">python3</span></code></li> </ul> <p>The PEP’s goal is to clarify the behavior for script end users, distribution providers, and script maintainers / authors.</p> </section> <section id="recommendation"> <h2><a class="toc-backref" href="#recommendation" role="doc-backlink">Recommendation</a></h2> <p>Our recommendations are detailed below. We call out any expectations that these recommendations are based upon.</p> <section id="for-python-runtime-distributors"> <h3><a class="toc-backref" href="#for-python-runtime-distributors" role="doc-backlink">For Python runtime distributors</a></h3> <ul class="simple"> <li>We expect Unix-like software distributions (including systems like macOS and Cygwin) to install the <code class="docutils literal notranslate"><span class="pre">python2</span></code> command into the default path whenever a version of the Python 2 interpreter is installed, and the same for <code class="docutils literal notranslate"><span class="pre">python3</span></code> and the Python 3 interpreter.</li> <li>When invoked, <code class="docutils literal notranslate"><span class="pre">python2</span></code> should run some version of the Python 2 interpreter, and <code class="docutils literal notranslate"><span class="pre">python3</span></code> should run some version of the Python 3 interpreter.</li> <li>If the <code class="docutils literal notranslate"><span class="pre">python</span></code> command is installed, it is expected to invoke either the same version of Python as the <code class="docutils literal notranslate"><span class="pre">python3</span></code> command or as the <code class="docutils literal notranslate"><span class="pre">python2</span></code> command.</li> <li>Distributors may choose to set the behavior of the <code class="docutils literal notranslate"><span class="pre">python</span></code> command as follows:<ul> <li><code class="docutils literal notranslate"><span class="pre">python2</span></code>,</li> <li><code class="docutils literal notranslate"><span class="pre">python3</span></code>,</li> <li>not provide <code class="docutils literal notranslate"><span class="pre">python</span></code> command, allow <code class="docutils literal notranslate"><span class="pre">python</span></code> to be configurable by an end user or a system administrator.</li> </ul> </li> <li>The Python 3.x <code class="docutils literal notranslate"><span class="pre">idle</span></code>, <code class="docutils literal notranslate"><span class="pre">pydoc</span></code>, and <code class="docutils literal notranslate"><span class="pre">python-config</span></code> commands should likewise be available as <code class="docutils literal notranslate"><span class="pre">idle3</span></code>, <code class="docutils literal notranslate"><span class="pre">pydoc3</span></code>, and <code class="docutils literal notranslate"><span class="pre">python3-config</span></code>; Python 2.x versions as <code class="docutils literal notranslate"><span class="pre">idle2</span></code>, <code class="docutils literal notranslate"><span class="pre">pydoc2</span></code>, and <code class="docutils literal notranslate"><span class="pre">python2-config</span></code>. The commands with no version number should either invoke the same version of Python as the <code class="docutils literal notranslate"><span class="pre">python</span></code> command, or not be available at all.</li> <li>When packaging third party Python scripts, distributors are encouraged to change less specific shebangs to more specific ones. This ensures software is used with the latest version of Python available, and it can remove a dependency on Python 2. The details on what specifics to set are left to the distributors; though. Example specifics could include:<ul> <li>Changing <code class="docutils literal notranslate"><span class="pre">python</span></code> shebangs to <code class="docutils literal notranslate"><span class="pre">python3</span></code> when Python 3.x is supported.</li> <li>Changing <code class="docutils literal notranslate"><span class="pre">python</span></code> shebangs to <code class="docutils literal notranslate"><span class="pre">python2</span></code> when Python 3.x is not yet supported.</li> <li>Changing <code class="docutils literal notranslate"><span class="pre">python3</span></code> shebangs to <code class="docutils literal notranslate"><span class="pre">python3.8</span></code> if the software is built with Python 3.8.</li> </ul> </li> <li>When a virtual environment (created by the <a class="pep reference internal" href="../pep-0405/" title="PEP 405 – Python Virtual Environments">PEP 405</a> <code class="docutils literal notranslate"><span class="pre">venv</span></code> package or a similar tool such as <code class="docutils literal notranslate"><span class="pre">virtualenv</span></code> or <code class="docutils literal notranslate"><span class="pre">conda</span></code>) is active, the <code class="docutils literal notranslate"><span class="pre">python</span></code> command should refer to the virtual environment’s interpreter and should always be available. The <code class="docutils literal notranslate"><span class="pre">python3</span></code> or <code class="docutils literal notranslate"><span class="pre">python2</span></code> command (according to the environment’s interpreter version) should also be available.</li> </ul> </section> <section id="for-python-script-publishers"> <h3><a class="toc-backref" href="#for-python-script-publishers" role="doc-backlink">For Python script publishers</a></h3> <ul class="simple"> <li>When reinvoking the interpreter from a Python script, querying <code class="docutils literal notranslate"><span class="pre">sys.executable</span></code> to avoid hardcoded assumptions regarding the interpreter location remains the preferred approach.</li> <li>Encourage your end users to use a virtual environment. This makes the user’s environment more predictable (possibly resulting in fewer issues), and helps avoid disrupting their system.</li> <li>For scripts that are only expected to be run in an activated virtual environment, shebang lines can be written as <code class="docutils literal notranslate"><span class="pre">#!/usr/bin/env</span> <span class="pre">python</span></code>, as this instructs the script to respect the active virtual environment.</li> <li>In cases where the script is expected to be executed outside virtual environments, developers will need to be aware of the following discrepancies across platforms and installation methods:<ul> <li>Older Linux distributions will provide a <code class="docutils literal notranslate"><span class="pre">python</span></code> command that refers to Python 2, and will likely not provide a <code class="docutils literal notranslate"><span class="pre">python2</span></code> command.</li> <li>Some newer Linux distributions will provide a <code class="docutils literal notranslate"><span class="pre">python</span></code> command that refers to Python 3.</li> <li>Some Linux distributions will not provide a <code class="docutils literal notranslate"><span class="pre">python</span></code> command at all by default, but will provide a <code class="docutils literal notranslate"><span class="pre">python3</span></code> command by default.</li> </ul> </li> <li>When potentially targeting these environments, developers may either use a Python package installation tool that rewrites shebang lines for the installed environment, provide instructions on updating shebang lines interactively, or else use more specific shebang lines that are tailored to the target environment.</li> <li>Scripts targeting both “<em>old systems</em>” and systems without the default <code class="docutils literal notranslate"><span class="pre">python</span></code> command need to make a compromise and document this situation. Avoiding shebangs (via the console_scripts Entry Points (<a class="footnote-reference brackets" href="#id19" id="id1">[9]</a>) or similar means) is the recommended workaround for this problem.</li> <li>Applications designed exclusively for a specific environment (such as a container or virtual environment) may continue to use the <code class="docutils literal notranslate"><span class="pre">python</span></code> command name.</li> </ul> </section> <section id="for-end-users-of-python"> <h3><a class="toc-backref" href="#for-end-users-of-python" role="doc-backlink">For end users of Python</a></h3> <ul class="simple"> <li>While far from being universally available, <code class="docutils literal notranslate"><span class="pre">python</span></code> remains the preferred spelling for explicitly invoking Python, as this is the spelling that virtual environments make consistently available across different platforms and Python installations.</li> <li>For software that is not distributed with (or developed for) your system, we recommend using a virtual environment, possibly with an environment manager like <code class="docutils literal notranslate"><span class="pre">conda</span></code> or <code class="docutils literal notranslate"><span class="pre">pipenv</span></code>, to help avoid disrupting your system Python installation.</li> </ul> <p>These recommendations are the outcome of the relevant python-dev discussions in March and July 2011 (<a class="footnote-reference brackets" href="#id11" id="id2">[1]</a>, <a class="footnote-reference brackets" href="#id12" id="id3">[2]</a>), February 2012 (<a class="footnote-reference brackets" href="#id14" id="id4">[4]</a>), September 2014 (<a class="footnote-reference brackets" href="#id16" id="id5">[6]</a>), discussion on GitHub in April 2018 (<a class="footnote-reference brackets" href="#id17" id="id6">[7]</a>), on python-dev in February 2019 (<a class="footnote-reference brackets" href="#id18" id="id7">[8]</a>), and during the PEP update review in May/June 2019 (<a class="footnote-reference brackets" href="#id20" id="id8">[10]</a>).</p> </section> </section> <section id="history-of-this-pep"> <h2><a class="toc-backref" href="#history-of-this-pep" role="doc-backlink">History of this PEP</a></h2> <p>In 2011, the majority of distributions aliased the <code class="docutils literal notranslate"><span class="pre">python</span></code> command to Python 2, but some started switching it to Python 3 (<a class="footnote-reference brackets" href="#id15" id="id9">[5]</a>). As some of the former distributions did not provide a <code class="docutils literal notranslate"><span class="pre">python2</span></code> command by default, there was previously no way for Python 2 code (or any code that invokes the Python 2 interpreter directly rather than via <code class="docutils literal notranslate"><span class="pre">sys.executable</span></code>) to reliably run on all Unix-like systems without modification, as the <code class="docutils literal notranslate"><span class="pre">python</span></code> command would invoke the wrong interpreter version on some systems, and the <code class="docutils literal notranslate"><span class="pre">python2</span></code> command would fail completely on others. This PEP originally provided a very simple mechanism to restore cross-platform support, with minimal additional work required on the part of distribution maintainers. Simplified, the recommendation was:</p> <ol class="arabic simple"> <li>The <code class="docutils literal notranslate"><span class="pre">python</span></code> command was preferred for code compatible with both Python 2 and 3 (since it was available on all systems, even those that already aliased it to Python 3).</li> <li>The <code class="docutils literal notranslate"><span class="pre">python</span></code> command should always invoke Python 2 (to prevent hard-to-diagnose errors when Python 2 code is run on Python 3).</li> <li>The <code class="docutils literal notranslate"><span class="pre">python2</span></code> and <code class="docutils literal notranslate"><span class="pre">python3</span></code> commands should be available to specify the version explicitly.</li> </ol> <p>However, these recommendations implicitly assumed that Python 2 would always be available. As Python 2 is nearing its end of life in 2020 (<a class="pep reference internal" href="../pep-0373/" title="PEP 373 – Python 2.7 Release Schedule">PEP 373</a>, <a class="pep reference internal" href="../pep-0404/" title="PEP 404 – Python 2.8 Un-release Schedule">PEP 404</a>), distributions are making Python 2 optional or removing it entirely. This means either removing the <code class="docutils literal notranslate"><span class="pre">python</span></code> command or switching it to invoke Python 3. Some distributors also decided that their users were better served by ignoring the PEP’s original recommendations, and provided system administrators with the freedom to configure their systems based on the needs of their particular environment.</p> </section> <section id="current-rationale"> <h2><a class="toc-backref" href="#current-rationale" role="doc-backlink">Current Rationale</a></h2> <p>As of 2019, activating a Python virtual environment (or its functional equivalent) prior to script execution is one way to obtain a consistent cross-platform and cross-distribution experience.</p> <p>Accordingly, publishers can expect users of the software to provide a suitable execution environment.</p> </section> <section id="future-changes-to-this-recommendation"> <h2><a class="toc-backref" href="#future-changes-to-this-recommendation" role="doc-backlink">Future Changes to this Recommendation</a></h2> <p>This recommendation will be periodically reviewed over the next few years, and updated when the core development team judges it appropriate. As a point of reference, regular maintenance releases for the Python 2.7 series will continue until January 2020.</p> </section> <section id="migration-notes"> <h2><a class="toc-backref" href="#migration-notes" role="doc-backlink">Migration Notes</a></h2> <p>This section does not contain any official recommendations from the core CPython developers. It’s merely a collection of notes regarding various aspects of migrating to Python 3 as the default version of Python for a system. They will hopefully be helpful to any distributions considering making such a change.</p> <ul> <li>The main barrier to a distribution switching the <code class="docutils literal notranslate"><span class="pre">python</span></code> command from <code class="docutils literal notranslate"><span class="pre">python2</span></code> to <code class="docutils literal notranslate"><span class="pre">python3</span></code> isn’t breakage within the distribution, but instead breakage of private third party scripts developed by sysadmins and other users. Updating the <code class="docutils literal notranslate"><span class="pre">python</span></code> command to invoke <code class="docutils literal notranslate"><span class="pre">python3</span></code> by default indicates that a distribution is willing to break such scripts with errors that are potentially quite confusing for users that aren’t familiar with the backwards incompatible changes in Python 3. For example, while the change of <code class="docutils literal notranslate"><span class="pre">print</span></code> from a statement to a builtin function is relatively simple for automated converters to handle, the SyntaxError from attempting to use the Python 2 notation in Python 3 may be confusing for users that are not aware of the change:<div class="highlight-pytb notranslate"><div class="highlight"><pre><span></span><span class="x">$ python3 -c 'print "Hello, world!"'</span> File <span class="nb">"<string>"</span>, line <span class="m">1</span> <span class="w"> </span><span class="nb">print</span> <span class="s2">"Hello, world!"</span> <span class="w"> </span><span class="pm">^</span> <span class="gr">SyntaxError</span>: <span class="n">Missing parentheses in call to 'print'. Did you mean print("Hello, world!")?</span> </pre></div> </div> <p>While this might be obvious for experienced Pythonistas, such scripts might even be run by people who are not familiar with Python at all. Avoiding breakage of such third party scripts was the key reason this PEP used to recommend that <code class="docutils literal notranslate"><span class="pre">python</span></code> continue to refer to <code class="docutils literal notranslate"><span class="pre">python2</span></code>.</p> </li> <li>The error message <code class="docutils literal notranslate"><span class="pre">python:</span> <span class="pre">command</span> <span class="pre">not</span> <span class="pre">found</span></code> tends to be surprisingly actionable, even for people unfamiliar with Python.</li> <li>The <code class="docutils literal notranslate"><span class="pre">pythonX.X</span></code> (e.g. <code class="docutils literal notranslate"><span class="pre">python3.6</span></code>) commands exist on modern systems, on which they invoke specific minor versions of the Python interpreter. It can be useful for distribution-specific packages to take advantage of these utilities if they exist, since it will prevent code breakage if the default minor version of a given major version is changed. However, scripts intending to be cross-platform should not rely on the presence of these utilities, but rather should be tested on several recent minor versions of the target major version, compensating, if necessary, for the small differences that exist between minor versions. This prevents the need for sysadmins to install many very similar versions of the interpreter.</li> <li>When the <code class="docutils literal notranslate"><span class="pre">pythonX.X</span></code> binaries are provided by a distribution, the <code class="docutils literal notranslate"><span class="pre">python2</span></code> and <code class="docutils literal notranslate"><span class="pre">python3</span></code> commands should refer to one of those files rather than being provided as a separate binary file.</li> <li>It is strongly encouraged that distribution-specific packages use <code class="docutils literal notranslate"><span class="pre">python3</span></code> (or <code class="docutils literal notranslate"><span class="pre">python2</span></code>) rather than <code class="docutils literal notranslate"><span class="pre">python</span></code>, even in code that is not intended to operate on other distributions. This will reduce problems if the distribution later decides to change the version of the Python interpreter that the <code class="docutils literal notranslate"><span class="pre">python</span></code> command invokes, or if a sysadmin installs a custom <code class="docutils literal notranslate"><span class="pre">python</span></code> command with a different major version than the distribution default.</li> <li>If the above point is adhered to and sysadmins are permitted to change the <code class="docutils literal notranslate"><span class="pre">python</span></code> command, then the <code class="docutils literal notranslate"><span class="pre">python</span></code> command should always be implemented as a link to the interpreter binary (or a link to a link) and not vice versa. That way, if a sysadmin does decide to replace the installed <code class="docutils literal notranslate"><span class="pre">python</span></code> file, they can do so without inadvertently deleting the previously installed binary.</li> <li>Even as the Python 2 interpreter becomes less common, it remains reasonable for scripts to continue to use the <code class="docutils literal notranslate"><span class="pre">python3</span></code> convention, rather than just <code class="docutils literal notranslate"><span class="pre">python</span></code>.</li> <li>If these conventions are adhered to, it will become the case that the <code class="docutils literal notranslate"><span class="pre">python</span></code> command is only executed in an interactive manner as a user convenience, or else when using a virtual environment or similar mechanism.</li> </ul> </section> <section id="backwards-compatibility"> <h2><a class="toc-backref" href="#backwards-compatibility" role="doc-backlink">Backwards Compatibility</a></h2> <p>A potential problem can arise if a script adhering to the <code class="docutils literal notranslate"><span class="pre">python2</span></code>/<code class="docutils literal notranslate"><span class="pre">python3</span></code> convention is executed on a system not supporting these commands. This is mostly a non-issue, since the sysadmin can simply create these symbolic links and avoid further problems. It is a significantly more obvious breakage than the sometimes cryptic errors that can arise when attempting to execute a script containing Python 2 specific syntax with a Python 3 interpreter or vice versa.</p> </section> <section id="application-to-the-cpython-reference-interpreter"> <h2><a class="toc-backref" href="#application-to-the-cpython-reference-interpreter" role="doc-backlink">Application to the CPython Reference Interpreter</a></h2> <p>While technically a new feature, the <code class="docutils literal notranslate"><span class="pre">make</span> <span class="pre">install</span></code> and <code class="docutils literal notranslate"><span class="pre">make</span> <span class="pre">bininstall</span></code> command in the 2.7 version of CPython were adjusted to create the following chains of symbolic links in the relevant <code class="docutils literal notranslate"><span class="pre">bin</span></code> directory (the final item listed in the chain is the actual installed binary, preceding items are relative symbolic links):</p> <div class="highlight-text notranslate"><div class="highlight"><pre><span></span>python -> python2 -> python2.7 python-config -> python2-config -> python2.7-config </pre></div> </div> <p>Similar adjustments were made to the macOS binary installer.</p> <p>This feature first appeared in the default installation process in CPython 2.7.3.</p> <p>The installation commands in the CPython 3.x series already create the appropriate symlinks. For example, CPython 3.2 creates:</p> <div class="highlight-text notranslate"><div class="highlight"><pre><span></span>python3 -> python3.2 idle3 -> idle3.2 pydoc3 -> pydoc3.2 python3-config -> python3.2-config </pre></div> </div> <p>And CPython 3.3 creates:</p> <div class="highlight-text notranslate"><div class="highlight"><pre><span></span>python3 -> python3.3 idle3 -> idle3.3 pydoc3 -> pydoc3.3 python3-config -> python3.3-config pysetup3 -> pysetup3.3 </pre></div> </div> <p>The implementation progress of these features in the default installers was managed on the tracker as issue #12627 (<a class="footnote-reference brackets" href="#id13" id="id10">[3]</a>).</p> </section> <section id="impact-on-python-environment-variables"> <h2><a class="toc-backref" href="#impact-on-python-environment-variables" role="doc-backlink">Impact on PYTHON* Environment Variables</a></h2> <p>The choice of target for the <code class="docutils literal notranslate"><span class="pre">python</span></code> command implicitly affects a distribution’s expected interpretation of the various Python related environment variables. The use of <code class="docutils literal notranslate"><span class="pre">*.pth</span></code> files in the relevant <code class="docutils literal notranslate"><span class="pre">site-packages</span></code> folder, the “per-user site packages” feature (see <code class="docutils literal notranslate"><span class="pre">python</span> <span class="pre">-m</span> <span class="pre">site</span></code>) or more flexible tools such as <code class="docutils literal notranslate"><span class="pre">virtualenv</span></code> are all more tolerant of the presence of multiple versions of Python on a system than the direct use of <code class="docutils literal notranslate"><span class="pre">PYTHONPATH</span></code>.</p> </section> <section id="exclusion-of-ms-windows"> <h2><a class="toc-backref" href="#exclusion-of-ms-windows" role="doc-backlink">Exclusion of MS Windows</a></h2> <p>This PEP deliberately excludes any proposals relating to Microsoft Windows, as devising an equivalent solution for Windows was deemed too complex to handle here. <a class="pep reference internal" href="../pep-0397/" title="PEP 397 – Python launcher for Windows">PEP 397</a> and the related discussion on the python-dev mailing list address this issue.</p> </section> <section id="references"> <h2><a class="toc-backref" href="#references" role="doc-backlink">References</a></h2> <aside class="footnote-list brackets"> <aside class="footnote brackets" id="id11" role="doc-footnote"> <dt class="label" id="id11">[<a href="#id2">1</a>]</dt> <dd>Support the /usr/bin/python2 symlink upstream (with bonus grammar class!) (<a class="reference external" href="https://mail.python.org/pipermail/python-dev/2011-March/108491.html">https://mail.python.org/pipermail/python-dev/2011-March/108491.html</a>)</aside> <aside class="footnote brackets" id="id12" role="doc-footnote"> <dt class="label" id="id12">[<a href="#id3">2</a>]</dt> <dd>Rebooting PEP 394 (aka Support the /usr/bin/python2 symlink upstream) (<a class="reference external" href="https://mail.python.org/pipermail/python-dev/2011-July/112322.html">https://mail.python.org/pipermail/python-dev/2011-July/112322.html</a>)</aside> <aside class="footnote brackets" id="id13" role="doc-footnote"> <dt class="label" id="id13">[<a href="#id10">3</a>]</dt> <dd>Implement PEP 394 in the CPython Makefile (<a class="reference external" href="https://github.com/python/cpython/issues/56836">https://github.com/python/cpython/issues/56836</a>)</aside> <aside class="footnote brackets" id="id14" role="doc-footnote"> <dt class="label" id="id14">[<a href="#id4">4</a>]</dt> <dd>PEP 394 request for pronouncement (python2 symlink in *nix systems) (<a class="reference external" href="https://mail.python.org/pipermail/python-dev/2012-February/116435.html">https://mail.python.org/pipermail/python-dev/2012-February/116435.html</a>)</aside> <aside class="footnote brackets" id="id15" role="doc-footnote"> <dt class="label" id="id15">[<a href="#id9">5</a>]</dt> <dd>Arch Linux announcement that their “python” link now refers Python 3 (<a class="reference external" href="https://www.archlinux.org/news/python-is-now-python-3/">https://www.archlinux.org/news/python-is-now-python-3/</a>)</aside> <aside class="footnote brackets" id="id16" role="doc-footnote"> <dt class="label" id="id16">[<a href="#id5">6</a>]</dt> <dd>PEP 394 - Clarification of what “python” command should invoke (<a class="reference external" href="https://mail.python.org/pipermail/python-dev/2014-September/136374.html">https://mail.python.org/pipermail/python-dev/2014-September/136374.html</a>)</aside> <aside class="footnote brackets" id="id17" role="doc-footnote"> <dt class="label" id="id17">[<a href="#id6">7</a>]</dt> <dd>PEP 394: Allow the <code class="docutils literal notranslate"><span class="pre">python</span></code> command to not be installed, and other minor edits (<a class="reference external" href="https://github.com/python/peps/pull/630">https://github.com/python/peps/pull/630</a>)</aside> <aside class="footnote brackets" id="id18" role="doc-footnote"> <dt class="label" id="id18">[<a href="#id7">8</a>]</dt> <dd>Another update for PEP 394 – The “python” Command on Unix-Like Systems (<a class="reference external" href="https://mail.python.org/pipermail/python-dev/2019-February/156272.html">https://mail.python.org/pipermail/python-dev/2019-February/156272.html</a>)</aside> <aside class="footnote brackets" id="id19" role="doc-footnote"> <dt class="label" id="id19">[<a href="#id1">9</a>]</dt> <dd>The console_scripts Entry Point (<a class="reference external" href="https://python-packaging.readthedocs.io/en/latest/command-line-scripts.html#the-console-scripts-entry-point">https://python-packaging.readthedocs.io/en/latest/command-line-scripts.html#the-console-scripts-entry-point</a>)</aside> <aside class="footnote brackets" id="id20" role="doc-footnote"> <dt class="label" id="id20">[<a href="#id8">10</a>]</dt> <dd>May 2019 PEP update review (<a class="reference external" href="https://github.com/python/peps/pull/989">https://github.com/python/peps/pull/989</a>)</aside> </aside> </section> <section id="copyright"> <h2><a class="toc-backref" href="#copyright" role="doc-backlink">Copyright</a></h2> <p>This document has been placed in the public domain.</p> </section> </section> <hr class="docutils" /> <p>Source: <a class="reference external" href="https://github.com/python/peps/blob/main/peps/pep-0394.rst">https://github.com/python/peps/blob/main/peps/pep-0394.rst</a></p> <p>Last modified: <a class="reference external" href="https://github.com/python/peps/commits/main/peps/pep-0394.rst">2024-02-26 08:33:49 GMT</a></p> </article> <nav id="pep-sidebar"> <h2>Contents</h2> <ul> <li><a class="reference internal" href="#abstract">Abstract</a></li> <li><a class="reference internal" href="#recommendation">Recommendation</a><ul> <li><a class="reference internal" href="#for-python-runtime-distributors">For Python runtime distributors</a></li> <li><a class="reference internal" href="#for-python-script-publishers">For Python script publishers</a></li> <li><a class="reference internal" href="#for-end-users-of-python">For end users of Python</a></li> </ul> </li> <li><a class="reference internal" href="#history-of-this-pep">History of this PEP</a></li> <li><a class="reference internal" href="#current-rationale">Current Rationale</a></li> <li><a class="reference internal" href="#future-changes-to-this-recommendation">Future Changes to this Recommendation</a></li> <li><a class="reference internal" href="#migration-notes">Migration Notes</a></li> <li><a class="reference internal" href="#backwards-compatibility">Backwards Compatibility</a></li> <li><a class="reference internal" href="#application-to-the-cpython-reference-interpreter">Application to the CPython Reference Interpreter</a></li> <li><a class="reference internal" href="#impact-on-python-environment-variables">Impact on PYTHON* Environment Variables</a></li> <li><a class="reference internal" href="#exclusion-of-ms-windows">Exclusion of MS Windows</a></li> <li><a class="reference internal" href="#references">References</a></li> <li><a class="reference internal" href="#copyright">Copyright</a></li> </ul> <br> <a id="source" href="https://github.com/python/peps/blob/main/peps/pep-0394.rst">Page Source (GitHub)</a> </nav> </section> <script src="../_static/colour_scheme.js"></script> <script src="../_static/wrap_tables.js"></script> <script src="../_static/sticky_banner.js"></script> </body> </html>