How to get argparse to use dashes in positional arguments

argparser-surprise.py

import argparse

parser = argparse.ArgumentParser()
parser.add_argument("table_name", metavar="table-name", help="blah", default=None)
parser.add_argument("--start-ts", help="blah2", default=None)
settings = parser.parse_args()
import pdb; pdb.set_trace()
print("goodbye")

import argparse

parser = argparse.ArgumentParser()
parser.add_argument("table_name", metavar="table-name", help="blah", default=None)
parser.add_argument("--start-ts", help="blah2", default=None)
settings = parser.parse_args()
print(settings)

The output is:

python fff.py wobble  --start-ts 1234
Namespace(start_ts='1234', table_name='wobble')

Argparse turns argument names with hyphens into underscores as in --start-ts => start_ts