Python-2.7.18

Introduction to Python 2

The Python 2 package contains the Python development environment. It is useful for object-oriented programming, writing scripts, prototyping large programs or developing entire applications. This version is for backward compatibility with other dependent packages.

[Note]

Note

Python2 has been deprecated by the upstream developers. Support for Python2 was discontinued on January 1st, 2020.

BLFS is attempting to use Python3 as much as possible, but some packages have not been updated to support Python3.

[Note]

Note

Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.

Package Information

Additional Downloads

Python 2 Dependencies

Recommended

Optional

BlueZ-5.70 and Valgrind-3.22.0

Optional (For more additional modules)

libnsl-2.0.1 and Tk-8.6.13

Editor Notes: https://wiki.linuxfromscratch.org/blfs/wiki/Python

Installation of Python 2

First, disable the installation of a script that overwrites a more recent script:

sed -i '/2to3/d' ./setup.py

Install Python 2 by running the following commands:

patch -Np1 -i ../Python-2.7.18-security_fixes-1.patch &&
./configure --prefix=/usr                              \
            --enable-shared                            \
            --with-system-expat                        \
            --with-system-ffi                          \
            --enable-unicode=ucs4                     &&
make

If you invoke the tests, they will run through twice. To test the results, issue: make -k test. Several tests are known to fail, including test_ftplib, test_ssl, test_urllib2_localnet, test_xml_etree, test_xml_etree_c, and test_minidom. These failures are due to OpenSSL-3 and Expat-2.4.6.

Now, as the root user:

make altinstall                                &&
ln -s python2.7        /usr/bin/python2        &&
ln -s python2.7-config /usr/bin/python2-config &&
chmod -v 755 /usr/lib/libpython2.7.so.1.0

Since Python 2 is in maintenance mode, and Python 3 is recommended by upstream for development, you probably do not need to install the documentation. However, if you still want to install documentation for both Python versions, be sure to define the PYTHONDOCS variable for the version you want to use, each time you need to consult the documentation. If you have downloaded the preformatted documentation from https://docs.python.org/download.html, install it as the root user:

install -v -dm755 /usr/share/doc/python-2.7.18 &&

tar --strip-components=1                     \
    --no-same-owner                          \
    --directory /usr/share/doc/python-2.7.18 \
    -xvf ../python-2.7.18-docs-html.tar.bz2 &&

find /usr/share/doc/python-2.7.18 -type d -exec chmod 0755 {} \; &&
find /usr/share/doc/python-2.7.18 -type f -exec chmod 0644 {} \;

Command Explanations

--with-system-expat: This switch enables linking against system version of Expat.

--with-system-ffi: This switch enables linking against system version of libffi.

--enable-unicode=ucs4: This switch enables 32-bit Unicode support in Python.

--with-ensurepip=yes : This switch enables building pip and setuptools packaging programs. setuptools is needed for building some Python modules. This switch is not recommended because this version of Python is no longer maintained.

--with-dbmliborder=bdb:gdbm:ndbm: Use this switch if you want to build Python DBM Module against Berkeley DB instead of GDBM.

make altinstall: This make target omits some default symbolic links that may interfere with Python 3.

chmod ...: Fix permissions for libraries to be consistent with other libraries.

Configuring Python 2

In order for python to find the installed documentation, you must add the following environment variable to individual user's or the system's profile:

export PYTHONDOCS=/usr/share/doc/python-2.7.18

Contents

Installed Programs: pydoc, python2 (symlink), python2-config (symlink), python2.7, python2.7-config, smtpd.py, and idle
Installed Library: libpython2.7.so
Installed Directories: /usr/{include,lib}/python2.7 and /usr/share/doc/python-2.7.18

Short Descriptions

idle

is a wrapper script that opens a Python aware GUI editor. For this script to run, you must have installed Tk before Python so that the Tkinter Python module is built

pydoc

is the Python documentation tool

python2

is an interpreted, interactive, object-oriented programming language

python2.7

is a version-specific name for the python program

smtpd.py

is an SMTP proxy implemented in Python