def under_scores_to_camel_case(string):
    """Transform a string from under score notation to camel case.

    Leaves capitalization in camel case intact

    Examples: 
        'under_score_word' --> 'UnderScoreWord' is renamed.
        'CamelCase' --> 'CamelCase' remains invariant.
    """
    return ''.join([i[0].capitalize() + i[1:] if len(i) > 1 else i[0].capitalize() for i in string.split('_')])