How to use multiple versions of Python without uninstallation

Question

I am faced with a unique situation, slightly trivial but painful.

I need to use Python 2.6.6 because NLTK is not ported to Python 3 (that\'s what I could gather).

Answer 1

The OP request is a little outdated, especially now that NLTK does have a py3.x port. see Install nltk 3.0 on Ubuntu 13.10 using tar.gz download

Here's how you can get python3 to work with NLTK.

$ sudo apt-get install python3-pip
$ sudo pip3 install pyyaml
$ wget http://www.nltk.org/nltk3-alpha/nltk-3.0a3.tar.gz
$ tar -xzvf nltk-3.0a3.tar.gz
$ cd nltk-3.0a3/
$ sudo python3 setup.py install
$ python3
>>> import nltk
>>> from nltk.corpus import brown
>>> print(brown.sents()[0])
['The', 'Fulton', 'County', 'Grand', 'Jury', 'said', 'Friday', 'an', 'investigation', 'of', "Atlanta's", 'recent', 'primary', 'election', 'produced', '``', 'no', 'evidence', "''", 'that', 'any', 'irregularities', 'took', 'place', '.']

Answer 2

If you're talking about shell, as in linux, if you install python 3, you can invoke it separately with the python3 command. Python 2 is just invoked using python.

At least this is my experience with Ubuntu-like systems, I haven't used other Linux environments.

I realize this question is almost a year old, but NLTK has been ported to Python 3 (or at least that was true as of writing this).

Answer 3

This page has an implementation of collections.Counter that works for Python 2.6:

• http://code.activestate.com/recipes/576611/

Answer 4

You can specify the version you want in the shebang line. I just ran into this when a VM my Ops guy set up had Python 2.6 in /usr/bin/python2.6, and I needed 2.7 for a few features. He installed it for me at /usr/bin/python2.7.

My old shebang:

#!/usr/bin/env python

stopped working, because /usr/bin/python was a link to /usr/bin/python2.6. What wound up fixing the problem, and working across Windows, Linux, and OSX, was changing the shebang to:

#!/usr/bin/env python2.7

It should work for any version, I believe.

Answer 5

not sure this is what you want, but I used to live with this for a long time http://www.portablepython.com/

Answer 6

Simplest solution : Rename the file in where your path is locations e.g: