| # 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 List |
| |
| from iceberg.api import Schema |
| from iceberg.api.types import get_projected_ids |
| |
| |
| def prune_columns(file_schema: Schema, expected_schema: Schema) -> List[str]: |
| """ |
| Given two Iceberg schema's returns a list of column_names for all id's in the |
| file schema that are projected in the expected schema |
| |
| Parameters |
| ---------- |
| file_schema : iceberg.api.Schema |
| An Iceberg schema of the file being read |
| expected_schema : iceberg.api.Schema |
| An Iceberg schema of the final projection |
| Returns |
| ------- |
| list |
| The column names in the file that matched ids in the expected schema |
| """ |
| return [column.name for column in file_schema.as_struct().fields |
| if column.id in get_projected_ids(expected_schema)] |