python argh/argparse: How can I pass a list as a command-line argument?

With argparse, you just use type=int

import argparse

parser = argparse.ArgumentParser()
parser.add_argument('-a', '--arg', nargs='+', type=int)
print parser.parse_args()

Example output:

$ python test.py -a 1 2 3
Namespace(arg=[1, 2, 3])

Edit: I'm not familiar with argh, but it seems to be just a wrapper around argparse and this worked for me:

import argh

@argh.arg('-a', '--arg', nargs='+', type=int)
def main(args):
    print args

parser = argh.ArghParser()
parser.add_commands([main])
parser.dispatch()

Example output:

$ python test.py main -a 1 2 3
Namespace(arg=[1, 2, 3], function=<function main at 0x.......>)

I order to have access to each parameter value, the following code may be helpful.

import argparse
parser = argparse.ArgumentParser()
parser.add_argument('-a', '--arg', nargs='+', type=int)
args = vars(parser.parse_args())

print "first parameter:" + str(args["arg"][0])
print "second parameter:" + str(args["arg"][1])
print "third parameter:" + str(args["arg"][2])