# # 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 string import typing from typing import Any, Optional, List, Tuple, Sequence, Mapping import uuid from pyspark.errors import PySparkValueError if typing.TYPE_CHECKING: from pyspark.sql.connect.session import SparkSession from pyspark.sql.connect.dataframe import DataFrame class SQLStringFormatter(string.Formatter): """ A standard ``string.Formatter`` in Python that can understand PySpark instances with basic Python objects. This object has to be clear after the use for single SQL query; cannot be reused across multiple SQL queries without cleaning. """ def __init__(self, session: "SparkSession") -> None: self._session: "SparkSession" = session self._temp_views: List[Tuple[DataFrame, str]] = [] def get_field(self, field_name: str, args: Sequence[Any], kwargs: Mapping[str, Any]) -> Any: obj, first = super().get_field(field_name, args, kwargs) return self._convert_value(obj, field_name), first def _convert_value(self, val: Any, field_name: str) -> Optional[str]: """ Converts the given value into a SQL string. """ from pyspark.sql.connect.dataframe import DataFrame from pyspark.sql.connect.column import Column from pyspark.sql.connect.expressions import ColumnReference from pyspark.sql.utils import get_lit_sql_str if isinstance(val, Column): expr = val._expr if isinstance(expr, ColumnReference): return expr._unparsed_identifier else: raise PySparkValueError( "%s in %s should be a plain column reference such as `df.col` " "or `col('column')`" % (val, field_name) ) elif isinstance(val, DataFrame): for df, n in self._temp_views: if df is val: return n name = "_pyspark_connect_temp_view_%s" % str(uuid.uuid4()).replace("-", "") self._temp_views.append((val, name)) return name elif isinstance(val, str): return get_lit_sql_str(val) else: return val def clear(self) -> None: pass