Installing Python 2.7 on Ubuntu

Installing Python 2.7 on Ubuntu

This week I upgraded the main installation of Python on my Ubuntu 10.04 machines to version 2.7. Here's a short documentation of this process.

Step 1: Prerequisites

The first step in Python's installation is running a
configure script which snoops around your system, looking for packages that it needs to build various capabilities and extensions with. Having these packages installed before running
configure makes sure it finds them.

Here are some packages that have to be installed to have various aspects of Python functioning:

sudo apt-get install libreadline-dev
sudo apt-get install libsqlite3-dev
sudo apt-get install libbz2-dev
sudo apt-get install libssl-dev

Step 2: Download and build Python

Go to http://www.python.org/. In the "Quick links" section on the left-hand side of the page, "Source distribution" is a direct link to the tarball. Download it. Unzip the tarball, and from the root of the created directory (which will be called
Python-2.7.2 or something similar, depending on the version):

./configure
make -j

I found that the default configure settings work fine for Ubuntu 10.04 and there's no real need to specify extra
--with flags.

You can now check that Python was correctly built by executing
./python and falling into its interactive terminal. If you want, you can also execute the Python test-suite with
make test, though it may take a long time to run (~10 minutes on a relatively fast machine).

Step 3: Install

In the same directory, run:

sudo make install

This installs Python into /usr/local/bin. Depending on the configuration of your system, you may want to add symlinks to the newly created
/usr/local/bin/python2.7 in
/usr/bin/ as well.

That's it, you now have Python 2.7 installed.

Step 4: Install some essential first modules

Python has a powerful packaging & installation machinery for its modules, but it doesn't come pre-installed with Python itself.

So it's a good idea to install
setuptools (or
distribute), followed by
pip.

From now, pip can be used to install other Python modules very conveniently. For example, all you need to have the
IPython shell installed is:

sudo pip install ipython