Convert CamelCase (or camelCase) to snake_case in Python

camel2snake.py

#!/usr/bin/env python
import sys
import re

def camel2snake(text, sep=r'_'):
    """Convert *text* from CamelCase (or camelCase) into snake_case."""
    rebounds = [r'([a-z])([A-Z])', r'([A-Z])([A-Z])']
    underscored_text = str(text)
    for b in rebounds:
        underscored_text = re.sub(b, (r'\g<1>'+ sep + r'\g<2>'), underscored_text)
    return underscored_text.lower()

if __name__ == "__main__":
    if len(sys.argv) > 1:
        print camel2snake(" ".join(sys.argv[1:]))