Move manage.py content to evap.__main__

[niklasmohrin]

This is in preparation for #2328, where we want to include the manage.py code, but cannot include the manage.py file because it is outside the evap module. Using __main__ allows running management commands with python -m evap if evap is installed into the environment. Running manage.py still works, as it uses the builtin runpy module to simulate running python -m evap.

[richardebeling]

Not that anyone would ever import this file, but is there a specific reason to remove the if __name__ == "__main__" guard?

[niklasmohrin]

No reason except brevity

[niklasmohrin]

I can add it back if you want

[Kakadus]

I mean ideally, this would be python -m evap directly... What about https://docs.python.org/3/library/runpy.html#runpy.run_module?

[niklasmohrin]

runpy sure is ... something :D It fixes the missing coverage, but it adds some complexity that we might not want. @richardebeling ?

[richardebeling]

Looks like the right thing to do to me. I'm not sure I get your points about missing coverage (you mean test coverage? Would that have been a problem?) and complexity (import runpy and runpy.run_module look canonical to me, I wouldn't care what they do under the hood -- do I need to care?), unless I'm missing something here I'm very fine with the current code

[niklasmohrin]

I was wondering whether runpy magic could break something like ./manage.py test --pdb, but it seems to work just fine. My points are

• without runpy, the line in __main__.py that calls main is not covered, but with runpy, it is (although the branch where __name__ is not __main__ is uncovered now :D)
• I also don't care what runpy does and don't want to care, I was just afraid that we would have to care some day. It also makes the manage.py file less approachable to first semester students, but I guess they have to accept our arcane magic anyways once they hit execute_from_command_line

I also think runpy is fun, so we can keep it if the above don't concern you :)

[richardebeling]

Alright, makes sense. I'm fine with both approaches.

[Kakadus]

I think both runpy or not is fine

[niklasmohrin]

I noticed that the usage text is sometimes messed up, for example python -m evap test --help prints usage: __main__.py test [snip]. Normally, Django wants to cover this up, but it doesn't seem to work with subcommands. Either way, the "fixed" variant would be usage: python -m django test [snip], which would also be wrong. If we were to really care about this, we would have to reimplement execute_from_command_line ourselves. I, personally, don't care