Is it ok to install both Python 2.7 and 3.5?

Question

Supposedly Python 2.7 is included native to OSX 10.8 and above (if I remember correctly), but I recently installed Python 3.5 to use for projects while I work through UDacit

Answer 1

I have installed two versions, 2.7, 3.4 and I do not have any problem by now. 3.4 I am using for my work project in eclipse environment, 2.7 for udacity course, like You ;).