xinrong-databricks commented on a change in pull request #33694: URL: https://github.com/apache/spark/pull/33694#discussion_r687013441
########## File path: python/pyspark/pandas/indexes/extension.py ########## @@ -0,0 +1,153 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You 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 +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# 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 Any, Callable, Optional, Union + +import pandas as pd +import numpy as np + +from pyspark.sql.functions import pandas_udf +from pyspark.sql.types import DataType + +from pyspark.pandas.indexes.base import Index +from pyspark.pandas.internal import SPARK_DEFAULT_INDEX_NAME +from pyspark.pandas.typedef.typehints import as_spark_type, infer_pd_series_spark_type + + +# TODO: Implement na_action similar functionality to pandas +# NB: Passing return_type into class cause Serialisation errors; instead pass at method level +class MapExtension: + def __init__(self, index: Index, na_action: Optional[str] = None): + self._index = index + if na_action is not None: + raise NotImplementedError("Currently do not support na_action functionality") + else: + self._na_action = na_action + + def map(self, mapper: Union[dict, Callable[[Any], Any], pd.Series]) -> Index: + """ + Single callable/entry point to map Index values. + + Parameters + ---------- + mapper: function, dict, or pd.Series + Mapping correspondence. + + Returns + ------- + Index + """ + if isinstance(mapper, dict): + return self._map_dict(mapper) + elif isinstance(mapper, pd.Series): + return self._map_series(mapper) + elif isinstance(mapper, Callable): + return self._map_lambda(mapper) + else: + raise TypeError("mapper can only be function, dict, or pd.Series.") + + def _map_dict(self, mapper: dict) -> Index: + """ + Helper method that maps Index values when mapper is in dict type. + + .. note:: Default return value for missing elements is np.nan + + Parameters + ---------- + mapper: dict + Key-value pairs that are used to instruct mapping from index value + to new value + + Returns + ------- + Index + """ + return_type = self._mapper_return_type(mapper) + + @pandas_udf(return_type) + def pyspark_mapper(col: pd.Series) -> pd.Series: + return col.apply(lambda i: mapper.get(i, np.nan)) # type: ignore + + return self._index._with_new_scol(pyspark_mapper(SPARK_DEFAULT_INDEX_NAME)) Review comment: Makes sense! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
