generate a lower-cased camelCase string from an underscore_string.
    For example: my_variable_name -> myVariableName

def lower_camel_case_from_underscores(string):
    """generate a lower-cased camelCase string from an underscore_string.
    For example: my_variable_name -> myVariableName"""
    components = string.split('_')
    string = components[0]
    for component in components[1:]:
        string += component[0].upper() + component[1:]
    return string