Fokko commented on code in PR #212: URL: https://github.com/apache/iceberg-python/pull/212#discussion_r1429705956
########## pyiceberg/table/name_mapping.py: ########## @@ -0,0 +1,203 @@ +# 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. +""" +Contains everything around the name mapping. + +More information can be found on here: +https://iceberg.apache.org/spec/#name-mapping-serialization +""" +from __future__ import annotations + +from abc import ABC, abstractmethod +from collections import ChainMap +from functools import cached_property, singledispatch +from typing import Any, Dict, Generic, List, TypeVar, Union + +from pydantic import Field, conlist, model_serializer + +from pyiceberg.schema import Schema, SchemaVisitor, visit +from pyiceberg.typedef import IcebergBaseModel, IcebergRootModel +from pyiceberg.types import ListType, MapType, NestedField, PrimitiveType, StructType + + +class MappedField(IcebergBaseModel): + field_id: int = Field(alias="field-id") + names: List[str] = conlist(str, min_length=1) + fields: List[MappedField] = Field(default_factory=list) + + @model_serializer + def ser_model(self) -> Dict[str, Any]: + """Set custom serializer to leave out the field when it is empty.""" + fields = {'fields': self.fields} if len(self.fields) > 0 else {} + return { + 'field-id': self.field_id, + 'names': self.names, + **fields, + } + + def __len__(self) -> int: + """Return the number of fields.""" + return len(self.fields) + + def __str__(self) -> str: + """Convert the mapped-field into a nicely formatted string.""" + # Otherwise the UTs fail because the order of the set can change + fields_str = ", ".join([str(e) for e in self.fields]) or "" + fields_str = " " + fields_str if fields_str else "" + return "([" + ", ".join(self.names) + "] -> " + (str(self.field_id) or "?") + fields_str + ")" + + +class NameMapping(IcebergRootModel[List[MappedField]]): + root: List[MappedField] + + @cached_property + def _field_by_id(self) -> Dict[int, MappedField]: + return visit_name_mapping(self, _IndexById()) + + @cached_property + def _field_by_name(self) -> Dict[str, MappedField]: + return visit_name_mapping(self, _IndexByName()) + + def id(self, name: str) -> int: + try: + return self._field_by_name[name].field_id Review Comment: What do you think of: ```python def find(self, *names: str) -> MappedField: name = '.'.join(names) try: return self._field_by_name[name] except KeyError as e: raise ValueError(f"Could not find field with name: {name}") from e ``` I think this is more pythonic, it will work as `find('a.b.c')`, `find('a', 'b', 'c')` and `find(*['a', 'b', 'c'])`. -- 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
