Example for turning a camelcase name into a _ separated filename.

camelcase_to_filename.py

def main(filename):
    data = open(filename).read()

    for char in range(65,91):
        letter = chr(char)
        data = data.replace(letter, '_' + letter.lower())
    
    print data[1:].replace('\n_','\n').replace('_test','_test.rb')


if __name__ == "__main__":
    import sys
    filename = sys.argv[1]
    main(filename)