I wouldn't suggest installing python3 from source directly to /usr/local/bin, since it can be difficult to get rid of it afterwards (Is there a easy way to update / install?) I'd suggest prefixing it with a specific install location (like /opt). Alternatively,
Anaconda is good for getting python.
Anyways, if you examine several scripts in /usr/bin and /usr/local/bin you will notice hashbangs of mostly this sort (This is on Linux Mint Cinnamon)
Code:
#!/usr/bin/python
#!/usr/bin/python3
Because these appear to reference directly to a preinstalled python, you should be fine as long as you don't overwrite /usr/bin/python or /usr/bin/python3. However, some may contain something like this
Code:
#!/usr/bin/env python
So whatever the PATH variable says python is at, it will use. If $PATH references python3 as python, that could be a issue!
