refactor: decouple pandas postprocessing operator (#18710)

superset/utils/pandas_postprocessing/select.py

@@ -0,0 +1,54 @@
+# 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 Dict, List, Optional
+
+from pandas import DataFrame
+
+from superset.utils.pandas_postprocessing.utils import validate_column_args
+
+
+@validate_column_args("columns", "drop", "rename")
+def select(
+    df: DataFrame,
+    columns: Optional[List[str]] = None,
+    exclude: Optional[List[str]] = None,
+    rename: Optional[Dict[str, str]] = None,
+) -> DataFrame:
+    """
+    Only select a subset of columns in the original dataset. Can be useful for
+    removing unnecessary intermediate results, renaming and reordering columns.
+
+    :param df: DataFrame on which the rolling period will be based.
+    :param columns: Columns which to select from the DataFrame, in the desired order.
+                    If left undefined, all columns will be selected. If columns are
+                    renamed, the original column name should be referenced here.
+    :param exclude: columns to exclude from selection. If columns are renamed, the new
+                    column name should be referenced here.
+    :param rename: columns which to rename, mapping source column to target column.
+                   For instance, `{'y': 'y2'}` will rename the column `y` to
+                   `y2`.
+    :return: Subset of columns in original DataFrame
+    :raises QueryObjectValidationError: If the request in incorrect
+    """
+    df_select = df.copy(deep=False)
+    if columns:
+        df_select = df_select[columns]
+    if exclude:
+        df_select = df_select.drop(exclude, axis=1)
+    if rename is not None:
+        df_select = df_select.rename(columns=rename)
+    return df_select