type=dict in argparse.add_argument()

Question

I\'m trying to set up a dictionary as optional argument (using argparse); the following line is what I have so far:

parser.add_argument(\'-i\',\'--image\', t         


        

Answer 1

Using simple lambda parsing is quite flexible:

parser.add_argument(
    '--fieldMap',
    type=lambda v: {k:int(v) for k,v in (x.split(':') for x in v.split(','))},
    help='comma-separated field:position pairs, e.g. Date:0,Amount:2,Payee:5,Memo:9'
)