Reduce code duplication in argparse config

[luis261]

There might still be more to improve here, but this seems like an improvement over the existing code, certainly less verbose and a bit more readable.

[CYB3RMX]

Could you please don't create requests before pulling your new changes? Because it causes conflict errors.

[luis261]

Yeah, that's my bad. I was aware of that when creating the initial set of PRs, but there was no way to avoid conflicts and still "demo" the different areas of improvement for the main module. I'll be sure to prevent conflicts in the future (I'll simply tackle the remaining topics sequentially).

Instead of pulling master to the branches on my forks for conflict resolution I'll just throw them away and create new branches.
This way we'll get a more concise history without the additional conflict resolution merges. I'll submit the new PRs (with the existing changes) this evening.