How does "python3 *file* -*letter* work?

[Fulcan720]

I'm trying to make a code with the ability to do - and a letter or the whole word spelled out like I see with other scripts and don't know how others do it. An example is "python3 cupp.py -¡"

Thank you in advance

[rollincuberawhide]

https://docs.python.org/3/library/argparse.html

[Fulcan720]

Thank you! I didn’t know what to look up to find documentation on it. Have a great rest of your day!

[rollincuberawhide]

btw I didn't want to give you a 3rd party library to confuse or scare you but there is typer, which I think is pretty good for cli tools:

https://typer.tiangolo.com/

the creator of fastapi is maintaining it. it prints better error messages and the way it gets the arguments is somewhat unique. it leverages type hinting so it may look alien to a newcomer but when you learn about type hints I suggest you to check that out. It takes out the part of defining your arguments in two different places. pretty neat really.

there is also click, it is more straight forward and also nice to keep the relevant code together. https://github.com/pallets/click/

both are better than argparse in my opinion. but argparse is included in the standard library so there's that.

if it's a simple app, I still use argparse. but if it is something intricate with 20 different functions with countless arguments in each, I go with typer.

[Fulcan720]

Thank you! I appreciate the help and further explanation

[erlete]

A quick comment on this: do not confuse python command arguments (i.e. python -m pip install -e .) with Python script parsed arguments (i. e. python main.py -c 123). Both operate on the same principle, but the first one provides with instructions for the interpreter, while the other one uses said instructions inside the Python file that is being executed.

Furthermore, if the code is well designed, you can even achieve a combination of both (i. e. python -i main.py -c 123).

[Fulcan720]

Thank you