On 3/30/11 10:32 AM, Neal Becker wrote:
I'm trying to combine 'choices' with a comma-seperated list of options, so I
could do e.g.,
--cheat=a,b
parser.add_argument ('--cheat', choices=('a','b','c'), type=lambda x:
x.split(','), default=[])
test.py --cheat a
error: argument --cheat: invalid choice: ['a'] (choose from 'a', 'b', 'c')
The validation of choice is failing, because parse returns a list, not an item.
Suggestions?
Do the validation in the type function.
import argparse
class ChoiceList(object):
def __init__(self, choices):
self.choices = choices
def __repr__(self):
return '%s(%r)' % (type(self).__name__, self.choices)
def __call__(self, csv):
args = csv.split(',')
remainder = sorted(set(args) - set(self.choices))
if remainder:
raise ValueError("invalid choices: %r (choose from %r)" %
(remainder, self.choices))
return args
parser = argparse.ArgumentParser()
parser.add_argument('--cheat', type=ChoiceList(['a','b','c']), default=[])
print parser.parse_args(['--cheat=a,b'])
parser.parse_args(['--cheat=a,b,d'])
--
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco
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