samredai commented on a change in pull request #4263: URL: https://github.com/apache/iceberg/pull/4263#discussion_r821053222
########## File path: python/src/iceberg/conversions.py ########## @@ -0,0 +1,251 @@ +# 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. +"""Utility module for various conversions around PrimitiveType implementations + +This module enables: + - Converting partition strings to built-in python objects + - Converting a value to a byte buffer + - Converting a byte buffer to a value + +Note: + Conversion logic varies based on the PrimitiveType implementation. Therefore conversion functions + are defined here as generic functions using the @singledispatch decorator. For each PrimitiveType + implementation, a concrete function is registered for each generic conversion function. For PrimitiveType + implementations that share the same conversion logic, registrations can be stacked. + +Example (registering `from_partition_to_py` logic for BooleanType): + >>> @from_partition_value_to_py.register(BooleanType) + >>> def _(type_, partition_value_as_str: str): + if partition_value_as_str is None: + return False + return partition_value_as_str.lower() == "true" + +Example (stacking registrations): + >>> @from_partition_value_to_py.register(FloatType) + >>> @from_partition_value_to_py.register(DoubleType) + >>> def _(type_, partition_value_as_str: str): + return float(partition_value_as_str) +""" +import struct +import uuid +from decimal import ROUND_HALF_UP, Decimal +from functools import singledispatch +from typing import Any + +from iceberg.types import ( + BinaryType, + BooleanType, + DateType, + DecimalType, + DoubleType, + FixedType, + FloatType, + IntegerType, + LongType, + StringType, + TimestampType, + TimestamptzType, + TimeType, + UUIDType, +) + +HIVE_NULL = "__HIVE_DEFAULT_PARTITION__" + + +@singledispatch +def from_partition_value_to_py(type_, partition_value_as_str: str): Review comment: Agreed, I'll rename `type_` to `primitive_type`, that's much clearer. For adding the type annotation, this should be feasible in that I don't think it will break the single dispatch decorator. Are you thinking we hint using the base primitive type class like `def from_partition_value_to_py(type_: PrimitiveType, partition_value_as_str: str):`? -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
