:param value:
    :return value:

def normalize_value(value, snake_case=True):
    """
    :param value:
    :return value:
    """
    if not isinstance(value, six.string_types):
        raise TypeError("the value passed to value must be a string")

    if snake_case:
        s1 = first_cap_re.sub(r'\1_\2', value)
        new_value = all_cap_re.sub(r'\1_\2', s1).lower()  # .replace('-', '_')
    else:
        new_value = value.lower()

    return new_value