Argparse is the standard Python module for handling (Unix style) command line options, in the expected way (which not all languages follow ). Or at least more or less the expected way; people are periodically surprised that by default argparse allows you to abbreviate long options (although you can safely turn that off if you assume Python 3.8 or later and you remember this corner case).

What I think of as the typical language API for specifying short and long options allows you to specify (at most) one of each; this is the API of, for example, the Go package I use for option handling . When I've written Python programs using argparse , I've followed this usage without thinking very much about it. However, argparse doesn't actually require you to restrict yourself this way. The add argument()_ accepts a list of option strings, and although the documentation's example shows a single short option and a single long option, you can give it more than one of each and it will work.

So yes, you can perfectly reasonably create an argparse option that can be invoked as either '--ns' or '--no-something', so that on the one hand you have a clear canonical version and on the other hand you have something short for convenience. If I'm going to do this (and sometimes I am), the thing I want to remember is that argparse's help output will report these options in the order I gave them to add argument()_ so I probably want to list the long one first, as the canonical and clearest form. In other words:

parser.add_argument("--no-something", "--ns", ....)

so that the -h output I get says:

--no-something, --ns     Don't do something

(If you have multiple '--no-...' options, abbreviated options aren't as compact as this '--ns' style. Of course it's a little bit unusual to have several long options that mean the same thing, but my view is that long options are sort of a zoo anyway and you might as well be convenient.)

Having multiple short (single letter) options for the same thing is also possible but much less in the Unix style, so I'm not sure I'd ever use it. One plausible use is mapping old short options to your real ones for compatibility (or just options that people are accustomed to using for some particular purpose from other programs, and keep using with yours).

(This is probably not news to anyone who's really used argparse. I'm partly writing this down so that I'll remember it in the future.)