Do a "Python3" check.

[Dev5H0]

Do a "python3" check in case the "python" run command fails.

[discretegames]

Moved this to runmany since it's not a runmanyext issue.

This is not a bad idea. In theory each language could have a list of ways to try to run. The problem is RunMany has no way to tell whether an output like python: command not found is the the output of the shell or the program. So sorry, it can't be done.

What you can do is put an indented settings JSON at the top of your .many file like

    { "languages": [{"name": "Python", "command": "python3"}] }
Python:
    print(9)

and the default command for Python will be overridden with python3.