<?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ <!ENTITY % general-entities SYSTEM "../general.ent"> %general-entities; ]> <sect1 id="ch-system-Python" role="wrap"> <?dbhtml filename="Python.html"?> <sect1info condition="script"> <productname>Python</productname> <productnumber>&python-version;</productnumber> <address>&python-url;</address> </sect1info> <title>Python-&python-version;</title> <indexterm zone="ch-system-Python"> <primary sortas="a-Python">Python</primary> </indexterm> <sect2 role="package"> <title/> <para>The Python 3 package contains the Python development environment. It is useful for object-oriented programming, writing scripts, prototyping large programs, or developing entire applications.</para> <segmentedlist> <segtitle>&buildtime;</segtitle> <segtitle>&diskspace;</segtitle> <seglistitem> <seg>&python-fin-sbu;</seg> <seg>&python-fin-du;</seg> </seglistitem> </segmentedlist> </sect2> <sect2 role="installation"> <title>Installation of Python 3</title> <para>Prepare Python for compilation:</para> <screen><userinput remap="configure">./configure --prefix=/usr \ --enable-shared \ --with-system-expat \ --with-system-ffi \ --enable-optimizations</userinput></screen> <variablelist> <title>The meaning of the configure options:</title> <varlistentry> <term><parameter>--with-system-expat</parameter></term> <listitem> <para>This switch enables linking against system version of <application>Expat</application>.</para> </listitem> </varlistentry> <varlistentry> <term><parameter>--with-system-ffi</parameter></term> <listitem> <para>This switch enables linking against system version of <application>libffi</application>.</para> </listitem> </varlistentry> <varlistentry> <term><parameter>--enable-optimizations</parameter></term> <listitem> <para>This switch enables stable, but expensive, optimizations.</para> </listitem> </varlistentry> </variablelist> <para>Compile the package:</para> <screen><userinput remap="make">make</userinput></screen> <para>Running the tests at this point is not recommended. The tests are known to hang indefinitely in the partial LFS environment. If desired, the tests can be rerun at the end of this chapter or when Python 3 is reinstalled in BLFS. To run the tests anyway, issue <command>make test</command>.</para> <para>Install the package:</para> <screen><userinput remap="install">make install</userinput></screen> <para>In several places we use the <command>pip3</command> command to install Python 3 programs and modules for all users as <systemitem class='username'>root</systemitem>. This conflicts with the Python developers recommendation to install packages into a virtual environment or the home directory of a regular user (by running <command>pip3</command> as this user). To this end, a multi-line warning is written when using <command>pip3</command> as the <systemitem class='username'>root</systemitem> user. The main reason of this recommendation is for avoiding a conflict with the system package manager (<command>dpkg</command> for example), but LFS does not have a system-wide package manager so this is not a problem. And, <command>pip3</command> will attempt to check for a new version of itself whenever it's run. As domain name resolving is not configured yet in LFS chroot environment, it will fail to check for a new version and produce a warning. Once we boot the LFS system and set up network connection, it will then produce a warning telling the user to update it from a pre-built wheel on PyPI if any new version is available. But LFS consider <command>pip3</command> a part of Python 3 so it should not be updated separately, and an update from a pre-built wheel will deviate from our purpose to build a Linux system from source code. So the warning for a new <command>pip3</command> version should be ignored as well. If desired, suppress these warnings by running the following commands:</para> <screen><userinput remap="install">cat > /etc/pip.conf << EOF <literal>[global] root-user-action = ignore disable-pip-version-check = true</literal> EOF </userinput></screen> <!-- <screen><userinput remap="install">sed -e '/def warn_if_run_as_root/a\ return' \ -i /usr/lib/python3.10/site-packages/pip/_internal/cli/req_command.py </userinput></screen> --> <important> <para> In LFS and BLFS we normally build and install Python modules with the <command>pip3</command> command. Please take care that the <command>pip3 install</command> commands in both the books should be run as the &root; user unless it's for a Python virtual environment. Running a <command>pip3 install</command> as a non-&root; user may seem to work fine, but it will cause the installed module to be inaccessible by other users. </para> <para> <command>pip3 install</command> will not reinstall an already installed module by default. For using the <command>pip3 install</command> command to upgrade a module (for example, from meson-0.61.3 to meson-0.62.0), insert the option <parameter>--upgrade</parameter> into the command line. If it's really necessary to downgrade a module or reinstall the same version for some reason, insert <parameter>--force-reinstall --no-deps</parameter> into the command line. </para> </important> <para>If desired, install the preformatted documentation:</para> <screen><userinput remap="install">install -v -dm755 /usr/share/doc/python-&python-version;/html tar --strip-components=1 \ --no-same-owner \ --no-same-permissions \ -C /usr/share/doc/python-&python-version;/html \ -xvf ../python-&python-version;-docs-html.tar.bz2</userinput></screen> <variablelist> <title>The meaning of the documentation install commands:</title> <varlistentry> <term><option>--no-same-owner</option> and <option>--no-same-permissions</option></term> <listitem> <para>Ensure the installed files have the correct ownership and permissions. Without these options, using <application>tar</application> will install the package files with the upstream creator's values. </para> </listitem> </varlistentry> </variablelist> </sect2> <sect2 id="contents-python" role="content"> <title>Contents of Python 3</title> <segmentedlist> <segtitle>Installed Programs</segtitle> <segtitle>Installed Library</segtitle> <segtitle>Installed Directories</segtitle> <seglistitem> <seg> 2to3, idle3, pip3, pydoc3, python3, and python3-config </seg> <seg> libpython&python-minor;.so and libpython3.so </seg> <seg> /usr/include/python&python-minor;, /usr/lib/python3, and /usr/share/doc/python-&python-version; </seg> </seglistitem> </segmentedlist> <variablelist> <bridgehead renderas="sect3">Short Descriptions</bridgehead> <?dbfo list-presentation="list"?> <?dbhtml list-presentation="table"?> <varlistentry id="python-2to3"> <term><command>2to3</command></term> <listitem> <para> is a <application>Python</application> program that reads <application>Python 2.x</application> source code and applies a series of fixes to transform it into valid <application>Python 3.x</application> code </para> <indexterm zone="ch-system-Python"> <primary sortas="b-2to3">2to3</primary> </indexterm> </listitem> </varlistentry> <varlistentry id="idle3"> <term><command>idle3</command></term> <listitem> <para> is a wrapper script that opens a <application>Python</application> aware GUI editor. For this script to run, you must have installed <application>Tk</application> before Python so that the Tkinter Python module is built </para> <indexterm zone="ch-system-Python"> <primary sortas="b-idle3">idle3</primary> </indexterm> </listitem> </varlistentry> <varlistentry id="pip3"> <term><command>pip3</command></term> <listitem> <para> The package installer for Python. You can use pip to install packages from Python Package Index and other indexes </para> <indexterm zone="ch-system-Python"> <primary sortas="b-pip3">pip3</primary> </indexterm> </listitem> </varlistentry> <varlistentry id="pydoc3"> <term><command>pydoc3</command></term> <listitem> <para> is the <application>Python</application> documentation tool </para> <indexterm zone="ch-system-Python"> <primary sortas="b-pydoc3">pydoc3</primary> </indexterm> </listitem> </varlistentry> <varlistentry id="python3"> <term><command>python3</command></term> <listitem> <para> is an interpreted, interactive, object-oriented programming language </para> <indexterm zone="ch-system-Python"> <primary sortas="b-python3">python3</primary> </indexterm> </listitem> </varlistentry> </variablelist> </sect2> </sect1>