HyukjinKwon commented on a change in pull request #32469: URL: https://github.com/apache/spark/pull/32469#discussion_r632448313
########## File path: python/pyspark/pandas/data_type_ops/datetime_ops.py ########## @@ -0,0 +1,99 @@ +# +# 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. +# + +import datetime +import warnings + +from pyspark.sql import functions as F +from pyspark.sql.types import TimestampType + +from pyspark.pandas.base import IndexOpsMixin +from pyspark.pandas.data_type_ops.base import DataTypeOps +from pyspark.pandas.typedef import as_spark_type + + +class DatetimeOps(DataTypeOps): + """ + The class for binary operations of pandas-on-Spark objects with spark type: TimestampType. + """ + + def __add__(self, left, right): + raise TypeError("addition can not be applied to date times.") + + def __sub__(self, left, right): + # Note that timestamp subtraction casts arguments to integer. This is to mimic pandas's + # behaviors. pandas returns 'timedelta64[ns]' from 'datetime64[ns]'s subtraction. + msg = ( + "Note that there is a behavior difference of timestamp subtraction. " + "The timestamp subtraction returns an integer in seconds, " + "whereas pandas returns 'timedelta64[ns]'." + ) + if isinstance(right, IndexOpsMixin) and isinstance(right.spark.data_type, TimestampType): + warnings.warn(msg, UserWarning) + return left.astype("long") - right.astype("long") + elif isinstance(right, datetime.datetime): + warnings.warn(msg, UserWarning) + return left.astype("long") - F.lit(right).cast(as_spark_type("long")) + else: + raise TypeError("datetime subtraction can only be applied to datetime series.") + + def __mul__(self, left, right): + raise TypeError("multiplication can not be applied to date times.") Review comment: Can we avoid to override these unsupported ones? It seems too reparative. You can do, for example, define a variable that holds a pretty name, and use it in the parent method that throws the exception: ```python class DataTypeOps: def __mul__(...): TypeError("multiplication can not be applied to %s" % self.pretty_name) class DatetimeOps(DataTypeOps): def __iniit__(...): self.pretty_name = "date times" ``` -- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
