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

You can use py launcher, that is installed with python distributable:

py -2    # default python 2
py -2.7  # specifically python 2.7
py -3    # default python 3
py -3.7  # specifically python 3.7

If you need to execute a script with a specific version you can do following:

py -3.7 my_script.py