# Copyright 2017 Neural Networks and Deep Learning lab, MIPT
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from typing import Union
from deeppavlov.core.common.registry import register
def str_lower(batch: Union[str, list, tuple]):
"""Recursively search for strings in a list and convert them to lowercase
batch: a string or a list containing strings at some level of nesting
the same structure where all strings are converted to lowercase
if isinstance(batch, str):
return list(map(str_lower, batch))