First parse! with optparse, then scan the ARGV and raise if ARGV is empty. Like so: op.parse! filename = ARGV.pop raise “Need to specify a file to process” unless filename The mandatory filename will not be processed by the OptionParser and will be left for you in ARGV – if it’s not there, just raise … Read more
S.Lott’s answer has already been accepted, but here’s a code sample for the archives: def foo_callback(option, opt, value, parser): setattr(parser.values, option.dest, value.split(‘,’)) parser = OptionParser() parser.add_option(‘-f’, ‘–foo’, type=”string”, action=’callback’, callback=foo_callback)
Try using the %default string placeholder: # This example taken from http://docs.python.org/library/optparse.html#generating-help parser.add_option(“-m”, “–mode”, default=”intermediate”, help=”interaction mode: novice, intermediate, ” “or expert [default: %default]”)
options, args = parser.parse_args() option_dict = vars(options) (Source is this python-ideas post.)
Replace args = parser.parse_args() with args, unknown = parser.parse_known_args() For example, import argparse parser = argparse.ArgumentParser() parser.add_argument(‘–foo’) args, unknown = parser.parse_known_args([‘–foo’, ‘BAR’, ‘spam’]) print(args) # Namespace(foo=’BAR’) print(unknown) # [‘spam’]
As of python 2.7, optparse is deprecated, and will hopefully go away in the future. argparse is better for all the reasons listed on its original page (https://code.google.com/archive/p/argparse/): handling positional arguments supporting sub-commands allowing alternative option prefixes like + and / handling zero-or-more and one-or-more style arguments producing more informative usage messages providing a much … Read more