How to have python 2 and 3 both on windows?

[Sunil KR via Python-list]

I have some scripts that are old and won't work under python2 and at the same 
time I am writing new scripts which will use python3. However, if python 2 and 
3 cannot co-exist in a windows box it will be impossible to transition
What I try:- remove all pythons and launchers- Use windows installer and 
install python2 in python27 directory- Use windows installer and install 
python3 in python310 directory- When installing python3 I opt in to install the 
launcher- Test with py -2 and py -3 and see that I get the expected prompt- 
just typing python gets me python2
-- 
https://mail.python.org/mailman/listinfo/python-list