a40c127 handle argparse behavior change in Python 3

Authored and Committed by adamwill 9 years ago
    handle argparse behavior change in Python 3
    
    In Py2, argparse naturally prints a nice error message if
    you don't specify a subparser. In Py3 it explodes unhelpfully.
    This magic incantation (thanks, StackOverflow!) fixes it.
    
        
file modified
+6 -1