Have do_nothing as default action for dictionary?

[Christopher Reimer]

Greetings,

I was playing around this piece of example code (written from memory).


def filter_text(key, value):

     def do_nothing(text): return text

     return {'this': call_this,

                   'that': call_that,

                   'what': do_nothing

                  }[key](value)


Is there a way to refactor the code to have the inner do_nothing 
function be the default action for the dictionary?

The original code was a series of if statements. The alternatives 
include using a lambda to replace the inner function or a try-except 
block on the dictionary to return value on KeyError exception.

What's the most pythonic and fastest?

Thank you,

Chris R.