rdblue commented on a change in pull request #4416: URL: https://github.com/apache/iceberg/pull/4416#discussion_r841252394
########## File path: python/src/iceberg/transforms.py ########## @@ -0,0 +1,240 @@ +# 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 math +import struct +from decimal import Decimal +from typing import Optional +from uuid import UUID + +import mmh3 # type: ignore + +from iceberg.types import ( + BinaryType, + DateType, + DecimalType, + FixedType, + IcebergType, + IntegerType, + LongType, + StringType, + TimestampType, + TimestamptzType, + TimeType, + UUIDType, +) + + +class Transform: + """Transform base class for concrete transforms. + + A base class to transform values and project predicates on partition values. + This class is not used directly. Instead, use one of module method to create the child classes. + + Args: + transform_string (str): name of the transform type + repr_string (str): string representation of a transform instance + """ + + def __init__(self, transform_string: str, repr_string: str): + self._transform_string = transform_string + self._repr_string = repr_string + + def __repr__(self): + return self._repr_string + + def __str__(self): + return self._transform_string + + def __call__(self, value): + return self.apply(value) + + def apply(self, value): + raise NotImplementedError() + + def can_transform(self, source: IcebergType) -> bool: + return False + + def result_type(self, source: IcebergType) -> IcebergType: + raise NotImplementedError() + + def preserves_order(self) -> bool: + return False + + def satisfies_order_of(self, other) -> bool: + return self == other + + def to_human_string(self, value) -> str: + if value is None: + return "null" + return str(value) + + def dedup_name(self) -> str: Review comment: We may want to make this a `@property`. -- 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]
