Comment by Sohcahtoa82

Outside of Python 2/3 differences, are Python interpreters not backwards compatible?

In other words, while obviously a program written for 3.3 won't work in 2.7, but will a program written for 3.3 fail to run in 3.8?

If it runs fine, why the need for multiple interpreters? I'd think you'd get by just fine by having the latest 2.x and 3.x installed.