When using Python's argparse module you can use parse_known_args() to parse only arguments that are known to the parser and any additional arguments are returned separately.
However, this fact is not denoted in the usage/help string. Of course I could put it in the description field of the parser, but I wonder if there's a nice way to include it in the usage line.
What I'm looking for is an output of e.g. usage: test [-h] ... instead of usage: test [-h]
I think you could do this with a combination of format_usage() and the ArgumentParser attribute usage. Note that that section shows usage as a keyword argument to the constructor, however, inspecting the source for usage shows that you can access it after construction as parser.usage.
I imagine your final solution would look something like:
parser = argparse.ArgumentParser()
# Add arguments...
usage = parser.format_usage()
parser.usage = usage.rstrip() + ' ...\n'
\n so that needs to be taken care of first: parser.usage = '%s ...\n' % parser.format_usage().rstrip()parse_known_args() is for the convenience of the programmer writing the program, not something that the user of the program needs to worry about. If you properly define your command-line arguments, argparse gives you something similar automatically:
>>> import argparse
>>> p = argparse.ArgumentParser(prog='command')
>>> x=p.add_argument("foo", nargs=argparse.REMAINDER)
>>> p.parse_args(["--help"])
usage: command [-h] ...
positional arguments:
foo
optional arguments:
-h, --help show this help message and exit
foo [foo ...] style it rather uncomfortable for my case since it's actually a single argument that may contain spaces in an environment where there are no quotes or backslashes, i.e. the only arg that can contain spaces is the last one by merging it with any non-args.
nargs=argparse.REMAINDER. That will put any remaining positional arguments in a list, and conveniently puts "..." in the help string as you want.