How do I update to Python 2.7?

It is already in the official repositories: http://packages.ubuntu.com/maverick/python2.7

sudo apt-get install python2.7

You then execute python2.7

P.S. Support for ubuntu 10.10 ends in April 2012: https://wiki.ubuntu.com/Releases

The Deadsnakes PPA is helpful for old and new versions of Python.

Lucid through Precise is supported with versions 2.x and 3.x available. Since you are looking for 10.10, the direct link is:

https://launchpad.net/~fkrull/+archive/deadsnakes?field.series_filter=maverick

1. Update Ubuntu 10.10 sources (credit).

   Because 10.10 is no longer supported.

   sudo sed -i -e 's/archive.ubuntu.com\|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list
   sudo apt-get update
   

2. Install add-apt-repository command (credit):

   This stops you from getting the sudo: add-apt-repository: command not found error in the next step.

   sudo apt-get install python-software-properties
   

3. Install Deadsnakes PPA (credit):

   sudo add-apt-repository ppa:fkrull/deadsnakes
   sudo apt-get update
   

4. Install Python 2.7:

   sudo apt-get install python2.7
   

5. Profit!

   $ python2.7 --version
   Python 2.7.4
   

sudo apt-get install python3.3

Same goes for python 2.4, 2.5, 3.1, 3.2, etc.