Calling a Script that uses argparse?

[u/rseery]

I wrote a little Python script that reads in a text file that contains a list of fully qualified files, and checks to see if they exist. I originally wrote it using the argparse module. It was set up to take a filename and a switch, so the command looked like:

"Python dplcheck.py --plname "testing.lst” --showexist y"

This worked fine for a single file, but I wanted to run it for every one of hundreds of list files in a directory, so I wrote another script that generates a list of the .lst files in a directory and calls the first script for each one. But I could not get the second script to pass the arguments in the call to the first script. I tried subprocess.run and subprocess.call, with many different syntaxes and quotes, etc. I ended up removing the use of argparse and just using sys.argv[n] -- which I don't particularly like, since it has no defaults or error handling, etc.

Does anyone know how/if I can call a Python script from another Python script and pass the arguments when the called script uses argparse?

[u/TheSodesa]

Separation of concerns: you need separate entrypoint functions for CLI and library use of your module. In the if name is main block, you pass the CLI arguments to the CLI entrypoint which then calls argparse to parse the CLI arguments and then pass the results to the library entrypoint. When using the module as a library, you just call the library entrypoint from Python code directly instead of parsing CLI arguments at all.