BUG: Allow string/path lists for multi-value Python API arguments

[axel-grc]

Multi-value (nargs="+") options were only comma-split for non-str types
because the neutralization gate skipped str-typed arguments. Passing a
list of paths through the Python API, e.g.
pct.pctcheckimagequality(reference=["a.nrrd","b.nrrd"]), serialized as
a single comma token but was never split, yielding one bogus filename
"a.nrrd,b.nrrd".

Neutralize the type of every nargs="+" option, including str/path lists,
then split comma tokens and re-cast each piece (str cast is a no-op).

[SimonRit]

I'm mostly unable to read this code. It would be good to add some documentation to required_dests and is there any way of testing this?

[acoussat]

I created a small test: acoussat@4bbce8d. The test does not pass with the previous version of the code but works using this branch. Should I add this test to this PR, or perhaps even push it to RTK?

[SimonRit]

I created a small test: acoussat@4bbce8d. The test does not pass with the previous version of the code but works using this branch. Should I add this test to this PR, or perhaps even push it to RTK?

Here is good I believe. Thanks!

[axel-grc]

Thanks @acoussat !
I think we could add one more test with the terminal-like command line in 1 string :
args = parser.parse_args( "--string-single a --number-single 1 --string-many a,b,c --number-many 1,2,3" )

[acoussat]

ArgumentParser.parse_args is not designed to parse a string directly, so we cannot test it with one single string.

https://docs.python.org/3/library/argparse.html#option-value-syntax
https://stackoverflow.com/questions/67368666/parsing-a-string-using-argparse