Search code examples
pythonpython-2.7argparseoptparse

Argparse to have type as choice

I have some old code which has optparse as their argument library. It has type as choice as one of the arguments 

type = "choice"

I am trying to convert my code to have argparse. What should I put in the type? If I add type = choice it throws an error:

NameError: global name 'choice' is not defined

What should be the value of type here if I am using argparse?

Solution

  • In optparse, choice type is just a special form of string. From the optparse documenattion:

    "choice" options are a subtype of "string" options. The choices option attribute (a sequence of strings) defines the set of allowed option arguments.

    You don't need to specify this as a type in argparse; all you need to provide is the choices. Remove the type argument altogether, or set it str if you want to be explicit.

    Also see the choices documentation for argparse; this is a lot more flexible than in optparse as this also allows for the choices to be of a type other than strings.