I'm writing a shell for a project of mine, which by design parses commands that looks like this:
COMMAND_NAME ARG1="Long Value" ARG2=123 [email protected]
My problem is that Python's command line parsing libraries (getopt and optparse) forces me to use '-' or '--' in front of the arguments. This behavior doesn't match my requirements.
Any ideas how can this be solved? Any existing library for this?
You could split them up with shlex.split(), which can handle the quoted values you have, and pretty easily parse this with a very simple regular expression. Or, you can just use regular expressions for both splitting and parsing. Or simply use split().
args = {}
for arg in shlex.split(cmdln_args):
key, value = arg.split('=', 1)
args[key] = value
Try to follow "Standards for Command Line Interfaces"
Convert your arguments (as Thomas suggested) to OptionParser format.
parser.parse_args(["--"+p if "=" in p else p for p in sys.argv[1:]])
If command-line arguments are not in sys.argv or a similar list but in a string then (as ironfroggy suggested) use shlex.split().
parser.parse_args(["--"+p if "=" in p else p for p in shlex.split(argsline)])
A small pythonic variation on Ironforggy's shlex answer:
args = dict( arg.split('=', 1) for arg in shlex.split(cmdln_args) )
oops... - corrected.
thanks, J.F. Sebastian (got to remember those single argument generator expressions).
What about optmatch (http://www.coderazzi.net/python/optmatch/index.htm)? Is not standard, but takes a different approach to options parsing, and it supports any prefix:
OptionMatcher.setMode(optionPrefix='-')
Without fairly intensive surgery on optparse or getopt, I don't believe you can sensibly make them parse your format. You can easily parse your own format, though, or translate it into something optparse could handle:
parser = optparse.OptionParser()
parser.add_option("--ARG1", dest="arg1", help="....")
parser.add_option(...)
...
newargs = sys.argv[:1]
for idx, arg in enumerate(sys.argv[1:])
parts = arg.split('=', 1)
if len(parts) < 2:
# End of options, don't translate the rest.
newargs.extend(sys.argv[idx+1:])
break
argname, argvalue = parts
newargs.extend(["--%s" % argname, argvalue])
parser.parse_args(newargs)
You may be interested in a little Python module I wrote to make handling of command line arguments even easier (open source and free to use) - http://freshmeat.net/projects/commando
