This was posted to the argparse mailing list by Steven Bethard and now we'd like some feedback from comp.lang.python.
We now have a branch[5] of argparse that supports an ``argparse.run`` function[6] which does some function introspection to build a command line parser from a function definition: ------------------------------ prog.py ------------------------------ import argparse def func(foo, bar, baz): """A function that foo's a bar with a baz. foo - The foo bar - The bar to be foo'd baz - The baz with which to foo. """ print foo, bar, baz if __name__ == '__main__': argparse.run(func) ------------------------------ cmdline ------------------------------ $ prog.py -h usage: prog.py [-h] foo bar baz A function that foo's a bar with a baz. positional arguments: foo The foo bar The bar to be foo'd baz The baz with which to foo. optional arguments: -h, --help show this help message and exit ---------------------------------------------------------------------- I'd love to hear some feedback on this. At the moment, the code can introspect argument names, types from defaults, types from annotations (in Python 3), help messages from docstrings, and knows how to convert multiple functions into subcommands. The code's compatible and tested on python 2.3 - 3.1. There are probably more things we could support [7], but I'd like to get some feedback on what we have so far. Some specific questions: * Do you think this is worth including in argparse? * Would you use the current ``argparse.run`` API in your own code? * If you wouldn't use it as-is, what additional features/modifications would you require? --Steve and Yuv PS: The authors of pyopt[1], opster[2], optfunc[3] and simpleopt[4] were CC'd, in the hopes that we can converge to a common API, but they didn't reply other than the pyopt guy (me) who wrote the patch. [0] SVN branch at: http://argparse.googlecode.com/svn/branches/function-arguments/ [1] http://code.google.com/p/pyopt/ [2] http://hg.piranha.org.ua/opster/ [3] http://github.com/simonw/optfunc/ [4] http://pypi.python.org/pypi/simpleopt/ [5] http://argparse.googlecode.com/svn/branches/function-arguments/ [6] The branch also adds ``ArgumentParser.add_function_arguments`` which ``argparse.run`` is built on top of. This method allows you to match function based arguments with other arguments as necessary, e.g.:: def items(n=10): return range(n) parser = argparse.ArgumentParser() parser.add_function_arguments(items) parser.add_argument('output_file') args = parser.parse_args() with open(args.output_file, 'w') as output_file: for item in args.items(): output_file.write("%d\n" % item) [7] I can imagine allowing the introspected values to be overridden with decorators, though it may be out of the scope of this patch. e.g.:: @annotate( dirname=positional(help='...'), listen=optional('-l', default='localhost', help='ip to listen on'), port=optional('-p', default=8000, help='port to listen on'), ...) def func(dirname, listen='localhost', port=8000, ...): -- http://mail.python.org/mailman/listinfo/python-list
