Default Ubuntu Python package version is 2.7, while in my Python class I use 3.4 and everything I keep typing python3 whenever I want to run python.
Want to turn 3.4 to your default? Easy, BASH made this available by providing space for aliases in the config. Aliases is not only for this function, I can define `donjajo` as alias of `ls` so now we are gonna re-define `python` to `python3`. Open your terminal and type this
$ nano ~/.bashrc
Then add to the last line of the file
Save and exit. Close the terminal and reopen for the changes to take effect.
I hope this helps 🙂