I feel somewhat evil about this.. however it's been incredibly useful

format_vars.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

def format_vars(format_string, format_vars=None):
    if not format_vars:
        format_vars = globals()
    return format_string.format(**format_vars)

if __name__ == "__main__":

    supdog = 'yo howdy'

    print format_vars("{__name__} says {supdog}")

Ignore the part where I override the function name within the function.. that's not for you to care about.