def convert_name_case(snake_case: str):
    """ snake_case to camelCase. For example, 'hello_world' -> 'helloWorld'. """
    if '.' in snake_case:
        # return '.'.join(convert_name_case(s) for s in snake_case.split('.'))
        return '.'.join(map(convert_name_case, snake_case.split('.')))
    
    if '_' not in snake_case:
        camel_case = snake_case
    else:
        segs = snake_case.split('_')
        camel_case = segs[0] + ''.join(x.title() for x in segs[1:])
    
    return camel_case