Source code for pyspark.sql.session

#
# 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 os
import sys
import warnings
from collections.abc import Sized
from functools import reduce
from threading import RLock
from types import TracebackType
from typing import (
    Any,
    ClassVar,
    Dict,
    Iterable,
    List,
    Optional,
    Tuple,
    Type,
    Union,
    cast,
    no_type_check,
    overload,
    TYPE_CHECKING,
)

from py4j.java_gateway import JavaObject

from pyspark import SparkConf, SparkContext
from pyspark.rdd import RDD
from pyspark.sql.column import _to_java_column
from pyspark.sql.conf import RuntimeConfig
from pyspark.sql.dataframe import DataFrame
from pyspark.sql.functions import lit
from pyspark.sql.pandas.conversion import SparkConversionMixin
from pyspark.sql.readwriter import DataFrameReader
from pyspark.sql.sql_formatter import SQLStringFormatter
from pyspark.sql.streaming import DataStreamReader
from pyspark.sql.types import (
    AtomicType,
    DataType,
    StructField,
    StructType,
    _make_type_verifier,
    _infer_schema,
    _has_nulltype,
    _merge_type,
    _create_converter,
    _parse_datatype_string,
    _from_numpy_type,
)
from pyspark.errors.exceptions.captured import install_exception_handler
from pyspark.sql.utils import is_timestamp_ntz_preferred, to_str

if TYPE_CHECKING:
    from pyspark.sql._typing import AtomicValue, RowLike, OptionalPrimitiveType
    from pyspark.sql.catalog import Catalog
    from pyspark.sql.pandas._typing import ArrayLike, DataFrameLike as PandasDataFrameLike
    from pyspark.sql.streaming import StreamingQueryManager
    from pyspark.sql.udf import UDFRegistration


__all__ = ["SparkSession"]


def _monkey_patch_RDD(sparkSession: "SparkSession") -> None:
    @no_type_check
    def toDF(self, schema=None, sampleRatio=None):
        """
        Converts current :class:`RDD` into a :class:`DataFrame`

        This is a shorthand for ``spark.createDataFrame(rdd, schema, sampleRatio)``

        Parameters
        ----------
        schema : :class:`pyspark.sql.types.DataType`, str or list, optional
            a :class:`pyspark.sql.types.DataType` or a datatype string or a list of
            column names, default is None.  The data type string format equals to
            :class:`pyspark.sql.types.DataType.simpleString`, except that top level struct type can
            omit the ``struct<>`` and atomic types use ``typeName()`` as their format, e.g. use
            ``byte`` instead of ``tinyint`` for :class:`pyspark.sql.types.ByteType`.
            We can also use ``int`` as a short name for :class:`pyspark.sql.types.IntegerType`.
        sampleRatio : float, optional
            the sample ratio of rows used for inferring

        Returns
        -------
        :class:`DataFrame`

        Examples
        --------
        >>> rdd = spark.range(1).rdd.map(lambda x: tuple(x))
        >>> rdd.collect()
        [(0,)]
        >>> rdd.toDF().show()
        +---+
        | _1|
        +---+
        |  0|
        +---+
        """
        return sparkSession.createDataFrame(self, schema, sampleRatio)

    RDD.toDF = toDF  # type: ignore[assignment]


# TODO(SPARK-38912): This method can be dropped once support for Python 3.8 is dropped
# In Python 3.9, the @property decorator has been made compatible with the
# @classmethod decorator (https://docs.python.org/3.9/library/functions.html#classmethod)
#
# @classmethod + @property is also affected by a bug in Python's docstring which was backported
# to Python 3.9.6 (https://github.com/python/cpython/pull/28838)
class classproperty(property):
    """Same as Python's @property decorator, but for class attributes.

    Examples
    --------
    >>> class Builder:
    ...    def build(self):
    ...        return MyClass()
    ...
    >>> class MyClass:
    ...     @classproperty
    ...     def builder(cls):
    ...         print("instantiating new builder")
    ...         return Builder()
    ...
    >>> c1 = MyClass.builder
    instantiating new builder
    >>> c2 = MyClass.builder
    instantiating new builder
    >>> c1 == c2
    False
    >>> isinstance(c1.build(), MyClass)
    True
    """

    def __get__(self, instance: Any, owner: Any = None) -> "SparkSession.Builder":
        # The "type: ignore" below silences the following error from mypy:
        # error: Argument 1 to "classmethod" has incompatible
        # type "Optional[Callable[[Any], Any]]";
        # expected "Callable[..., Any]"  [arg-type]
        return classmethod(self.fget).__get__(None, owner)()  # type: ignore


[docs]class SparkSession(SparkConversionMixin): """The entry point to programming Spark with the Dataset and DataFrame API. A SparkSession can be used to create :class:`DataFrame`, register :class:`DataFrame` as tables, execute SQL over tables, cache tables, and read parquet files. To create a :class:`SparkSession`, use the following builder pattern: .. versionchanged:: 3.4.0 Supports Spark Connect. .. autoattribute:: builder :annotation: Examples -------- Create a Spark session. >>> spark = ( ... SparkSession.builder ... .master("local") ... .appName("Word Count") ... .config("spark.some.config.option", "some-value") ... .getOrCreate() ... ) Create a Spark session with Spark Connect. >>> spark = ( ... SparkSession.builder ... .remote("sc://localhost") ... .appName("Word Count") ... .config("spark.some.config.option", "some-value") ... .getOrCreate() ... ) # doctest: +SKIP """ class Builder: """Builder for :class:`SparkSession`.""" _lock = RLock() def __init__(self) -> None: self._options: Dict[str, Any] = {} @overload def config(self, *, conf: SparkConf) -> "SparkSession.Builder": ... @overload def config(self, key: str, value: Any) -> "SparkSession.Builder": ... @overload def config(self, *, map: Dict[str, "OptionalPrimitiveType"]) -> "SparkSession.Builder": ... def config( self, key: Optional[str] = None, value: Optional[Any] = None, conf: Optional[SparkConf] = None, *, map: Optional[Dict[str, "OptionalPrimitiveType"]] = None, ) -> "SparkSession.Builder": """Sets a config option. Options set using this method are automatically propagated to both :class:`SparkConf` and :class:`SparkSession`'s own configuration. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Parameters ---------- key : str, optional a key name string for configuration property value : str, optional a value for configuration property conf : :class:`SparkConf`, optional an instance of :class:`SparkConf` map: dictionary, optional a dictionary of configurations to set .. versionadded:: 3.4.0 Returns ------- :class:`SparkSession.Builder` Examples -------- For an existing class:`SparkConf`, use `conf` parameter. >>> from pyspark.conf import SparkConf >>> SparkSession.builder.config(conf=SparkConf()) <pyspark.sql.session.SparkSession.Builder... For a (key, value) pair, you can omit parameter names. >>> SparkSession.builder.config("spark.some.config.option", "some-value") <pyspark.sql.session.SparkSession.Builder... Additionally, you can pass a dictionary of configurations to set. >>> SparkSession.builder.config( ... map={"spark.some.config.number": 123, "spark.some.config.float": 0.123}) <pyspark.sql.session.SparkSession.Builder... """ def check_startup_urls(k: str, v: str) -> None: if k == "spark.master": if "spark.remote" in self._options or "SPARK_REMOTE" in os.environ: raise RuntimeError( "Spark master cannot be configured with Spark Connect server; " "however, found URL for Spark Connect [%s]" % self._options.get("spark.remote", os.environ.get("SPARK_REMOTE")) ) elif k == "spark.remote": if "spark.master" in self._options or "MASTER" in os.environ: raise RuntimeError( "Spark Connect server cannot be configured with Spark master; " "however, found URL for Spark master [%s]" % self._options.get("spark.master", os.environ.get("MASTER")) ) if ("SPARK_REMOTE" in os.environ and os.environ["SPARK_REMOTE"] != v) and ( "SPARK_LOCAL_REMOTE" in os.environ and not v.startswith("local") ): raise RuntimeError( "Only one Spark Connect client URL can be set; however, got a " "different URL [%s] from the existing [%s]" % (os.environ["SPARK_REMOTE"], v) ) with self._lock: if conf is not None: for (k, v) in conf.getAll(): check_startup_urls(k, v) self._options[k] = v elif map is not None: for k, v in map.items(): # type: ignore[assignment] v = to_str(v) # type: ignore[assignment] check_startup_urls(k, v) self._options[k] = v else: value = to_str(value) check_startup_urls(key, value) # type: ignore[arg-type] self._options[cast(str, key)] = value return self def master(self, master: str) -> "SparkSession.Builder": """Sets the Spark master URL to connect to, such as "local" to run locally, "local[4]" to run locally with 4 cores, or "spark://master:7077" to run on a Spark standalone cluster. .. versionadded:: 2.0.0 Parameters ---------- master : str a url for spark master Returns ------- :class:`SparkSession.Builder` Examples -------- >>> SparkSession.builder.master("local") <pyspark.sql.session.SparkSession.Builder... """ return self.config("spark.master", master) def remote(self, url: str) -> "SparkSession.Builder": """Sets the Spark remote URL to connect to, such as "sc://host:port" to run it via Spark Connect server. .. versionadded:: 3.4.0 Parameters ---------- url : str URL to Spark Connect server Returns ------- :class:`SparkSession.Builder` Examples -------- >>> SparkSession.builder.remote("sc://localhost") # doctest: +SKIP <pyspark.sql.session.SparkSession.Builder... """ return self.config("spark.remote", url) def appName(self, name: str) -> "SparkSession.Builder": """Sets a name for the application, which will be shown in the Spark web UI. If no application name is set, a randomly generated name will be used. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Parameters ---------- name : str an application name Returns ------- :class:`SparkSession.Builder` Examples -------- >>> SparkSession.builder.appName("My app") <pyspark.sql.session.SparkSession.Builder... """ return self.config("spark.app.name", name) def enableHiveSupport(self) -> "SparkSession.Builder": """Enables Hive support, including connectivity to a persistent Hive metastore, support for Hive SerDes, and Hive user-defined functions. .. versionadded:: 2.0.0 Returns ------- :class:`SparkSession.Builder` Examples -------- >>> SparkSession.builder.enableHiveSupport() <pyspark.sql.session.SparkSession.Builder... """ return self.config("spark.sql.catalogImplementation", "hive") def getOrCreate(self) -> "SparkSession": """Gets an existing :class:`SparkSession` or, if there is no existing one, creates a new one based on the options set in this builder. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Returns ------- :class:`SparkSession` Examples -------- This method first checks whether there is a valid global default SparkSession, and if yes, return that one. If no valid global default SparkSession exists, the method creates a new SparkSession and assigns the newly created SparkSession as the global default. >>> s1 = SparkSession.builder.config("k1", "v1").getOrCreate() >>> s1.conf.get("k1") == "v1" True The configuration of the SparkSession can be changed afterwards >>> s1.conf.set("k1", "v1_new") >>> s1.conf.get("k1") == "v1_new" True In case an existing SparkSession is returned, the config options specified in this builder will be applied to the existing SparkSession. >>> s2 = SparkSession.builder.config("k2", "v2").getOrCreate() >>> s1.conf.get("k1") == s2.conf.get("k1") == "v1_new" True >>> s1.conf.get("k2") == s2.conf.get("k2") == "v2" True """ from pyspark.context import SparkContext from pyspark.conf import SparkConf opts = dict(self._options) with self._lock: if "SPARK_REMOTE" in os.environ or "spark.remote" in opts: with SparkContext._lock: from pyspark.sql.connect.session import SparkSession as RemoteSparkSession if ( SparkContext._active_spark_context is None and SparkSession._instantiatedSession is None ): url = opts.get("spark.remote", os.environ.get("SPARK_REMOTE")) if url.startswith("local"): os.environ["SPARK_LOCAL_REMOTE"] = "1" RemoteSparkSession._start_connect_server(url, opts) url = "sc://localhost" os.environ["SPARK_REMOTE"] = url opts["spark.remote"] = url return RemoteSparkSession.builder.config(map=opts).getOrCreate() elif "SPARK_LOCAL_REMOTE" in os.environ: url = "sc://localhost" os.environ["SPARK_REMOTE"] = url opts["spark.remote"] = url return RemoteSparkSession.builder.config(map=opts).getOrCreate() else: raise RuntimeError( "Cannot start a remote Spark session because there " "is a regular Spark session already running." ) session = SparkSession._instantiatedSession if session is None or session._sc._jsc is None: sparkConf = SparkConf() for key, value in self._options.items(): sparkConf.set(key, value) # This SparkContext may be an existing one. sc = SparkContext.getOrCreate(sparkConf) # Do not update `SparkConf` for existing `SparkContext`, as it's shared # by all sessions. session = SparkSession(sc, options=self._options) else: getattr( getattr(session._jvm, "SparkSession$"), "MODULE$" ).applyModifiableSettings(session._jsparkSession, self._options) return session # TODO(SPARK-38912): Replace @classproperty with @classmethod + @property once support for # Python 3.8 is dropped. # # In Python 3.9, the @property decorator has been made compatible with the # @classmethod decorator (https://docs.python.org/3.9/library/functions.html#classmethod) # # @classmethod + @property is also affected by a bug in Python's docstring which was backported # to Python 3.9.6 (https://github.com/python/cpython/pull/28838)
[docs] @classproperty def builder(cls) -> Builder: """Creates a :class:`Builder` for constructing a :class:`SparkSession`.""" return cls.Builder()
_instantiatedSession: ClassVar[Optional["SparkSession"]] = None _activeSession: ClassVar[Optional["SparkSession"]] = None def __init__( self, sparkContext: SparkContext, jsparkSession: Optional[JavaObject] = None, options: Dict[str, Any] = {}, ): self._sc = sparkContext self._jsc = self._sc._jsc self._jvm = self._sc._jvm assert self._jvm is not None if jsparkSession is None: if ( self._jvm.SparkSession.getDefaultSession().isDefined() and not self._jvm.SparkSession.getDefaultSession().get().sparkContext().isStopped() ): jsparkSession = self._jvm.SparkSession.getDefaultSession().get() getattr(getattr(self._jvm, "SparkSession$"), "MODULE$").applyModifiableSettings( jsparkSession, options ) else: jsparkSession = self._jvm.SparkSession(self._jsc.sc(), options) else: getattr(getattr(self._jvm, "SparkSession$"), "MODULE$").applyModifiableSettings( jsparkSession, options ) self._jsparkSession = jsparkSession _monkey_patch_RDD(self) install_exception_handler() # If we had an instantiated SparkSession attached with a SparkContext # which is stopped now, we need to renew the instantiated SparkSession. # Otherwise, we will use invalid SparkSession when we call Builder.getOrCreate. if ( SparkSession._instantiatedSession is None or SparkSession._instantiatedSession._sc._jsc is None ): SparkSession._instantiatedSession = self SparkSession._activeSession = self assert self._jvm is not None self._jvm.SparkSession.setDefaultSession(self._jsparkSession) self._jvm.SparkSession.setActiveSession(self._jsparkSession) def _repr_html_(self) -> str: return """ <div> <p><b>SparkSession - {catalogImplementation}</b></p> {sc_HTML} </div> """.format( catalogImplementation=self.conf.get("spark.sql.catalogImplementation"), sc_HTML=self.sparkContext._repr_html_(), ) @property def _jconf(self) -> "JavaObject": """Accessor for the JVM SQL-specific configurations""" return self._jsparkSession.sessionState().conf()
[docs] def newSession(self) -> "SparkSession": """ Returns a new :class:`SparkSession` as new session, that has separate SQLConf, registered temporary views and UDFs, but shared :class:`SparkContext` and table cache. .. versionadded:: 2.0.0 Returns ------- :class:`SparkSession` Spark session if an active session exists for the current thread Examples -------- >>> spark.newSession() <...SparkSession object ...> """ return self.__class__(self._sc, self._jsparkSession.newSession())
[docs] @classmethod def getActiveSession(cls) -> Optional["SparkSession"]: """ Returns the active :class:`SparkSession` for the current thread, returned by the builder .. versionadded:: 3.0.0 Returns ------- :class:`SparkSession` Spark session if an active session exists for the current thread Examples -------- >>> s = SparkSession.getActiveSession() >>> df = s.createDataFrame([('Alice', 1)], ['name', 'age']) >>> df.select("age").show() +---+ |age| +---+ | 1| +---+ """ from pyspark import SparkContext sc = SparkContext._active_spark_context if sc is None: return None else: assert sc._jvm is not None if sc._jvm.SparkSession.getActiveSession().isDefined(): SparkSession(sc, sc._jvm.SparkSession.getActiveSession().get()) return SparkSession._activeSession else: return None
@property def sparkContext(self) -> SparkContext: """ Returns the underlying :class:`SparkContext`. .. versionadded:: 2.0.0 Returns ------- :class:`SparkContext` Examples -------- >>> spark.sparkContext <SparkContext master=... appName=...> Create an RDD from the Spark context >>> rdd = spark.sparkContext.parallelize([1, 2, 3]) >>> rdd.collect() [1, 2, 3] """ return self._sc @property def version(self) -> str: """ The version of Spark on which this application is running. .. versionadded:: 2.0.0 Returns ------- str the version of Spark in string. Examples -------- >>> _ = spark.version """ return self._jsparkSession.version() @property def conf(self) -> RuntimeConfig: """Runtime configuration interface for Spark. This is the interface through which the user can get and set all Spark and Hadoop configurations that are relevant to Spark SQL. When getting the value of a config, this defaults to the value set in the underlying :class:`SparkContext`, if any. .. versionadded:: 2.0.0 Returns ------- :class:`pyspark.sql.conf.RuntimeConfig` Examples -------- >>> spark.conf <pyspark.sql.conf.RuntimeConfig object ...> Set a runtime configuration for the session >>> spark.conf.set("key", "value") >>> spark.conf.get("key") 'value' """ if not hasattr(self, "_conf"): self._conf = RuntimeConfig(self._jsparkSession.conf()) return self._conf @property def catalog(self) -> "Catalog": """Interface through which the user may create, drop, alter or query underlying databases, tables, functions, etc. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Returns ------- :class:`Catalog` Examples -------- >>> spark.catalog <...Catalog object ...> Create a temp view, show the list, and drop it. >>> spark.range(1).createTempView("test_view") >>> spark.catalog.listTables() [Table(name='test_view', catalog=None, namespace=[], description=None, ... >>> _ = spark.catalog.dropTempView("test_view") """ from pyspark.sql.catalog import Catalog if not hasattr(self, "_catalog"): self._catalog = Catalog(self) return self._catalog @property def udf(self) -> "UDFRegistration": """Returns a :class:`UDFRegistration` for UDF registration. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Returns ------- :class:`UDFRegistration` Examples -------- Register a Python UDF, and use it in SQL. >>> strlen = spark.udf.register("strlen", lambda x: len(x)) >>> spark.sql("SELECT strlen('test')").show() +------------+ |strlen(test)| +------------+ | 4| +------------+ """ from pyspark.sql.udf import UDFRegistration return UDFRegistration(self)
[docs] def range( self, start: int, end: Optional[int] = None, step: int = 1, numPartitions: Optional[int] = None, ) -> DataFrame: """ Create a :class:`DataFrame` with single :class:`pyspark.sql.types.LongType` column named ``id``, containing elements in a range from ``start`` to ``end`` (exclusive) with step value ``step``. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Parameters ---------- start : int the start value end : int, optional the end value (exclusive) step : int, optional the incremental step (default: 1) numPartitions : int, optional the number of partitions of the DataFrame Returns ------- :class:`DataFrame` Examples -------- >>> spark.range(1, 7, 2).show() +---+ | id| +---+ | 1| | 3| | 5| +---+ If only one argument is specified, it will be used as the end value. >>> spark.range(3).show() +---+ | id| +---+ | 0| | 1| | 2| +---+ """ if numPartitions is None: numPartitions = self._sc.defaultParallelism if end is None: jdf = self._jsparkSession.range(0, int(start), int(step), int(numPartitions)) else: jdf = self._jsparkSession.range(int(start), int(end), int(step), int(numPartitions)) return DataFrame(jdf, self)
def _inferSchemaFromList( self, data: Iterable[Any], names: Optional[List[str]] = None ) -> StructType: """ Infer schema from list of Row, dict, or tuple. Parameters ---------- data : iterable list of Row, dict, or tuple names : list, optional list of column names Returns ------- :class:`pyspark.sql.types.StructType` """ if not data: raise ValueError("can not infer schema from empty dataset") infer_dict_as_struct = self._jconf.inferDictAsStruct() infer_array_from_first_element = self._jconf.legacyInferArrayTypeFromFirstElement() prefer_timestamp_ntz = is_timestamp_ntz_preferred() schema = reduce( _merge_type, ( _infer_schema( row, names, infer_dict_as_struct=infer_dict_as_struct, infer_array_from_first_element=infer_array_from_first_element, prefer_timestamp_ntz=prefer_timestamp_ntz, ) for row in data ), ) if _has_nulltype(schema): raise ValueError("Some of types cannot be determined after inferring") return schema def _inferSchema( self, rdd: RDD[Any], samplingRatio: Optional[float] = None, names: Optional[List[str]] = None, ) -> StructType: """ Infer schema from an RDD of Row, dict, or tuple. Parameters ---------- rdd : :class:`RDD` an RDD of Row, dict, or tuple samplingRatio : float, optional sampling ratio, or no sampling (default) names : list, optional Returns ------- :class:`pyspark.sql.types.StructType` """ first = rdd.first() if isinstance(first, Sized) and len(first) == 0: raise ValueError("The first row in RDD is empty, can not infer schema") infer_dict_as_struct = self._jconf.inferDictAsStruct() infer_array_from_first_element = self._jconf.legacyInferArrayTypeFromFirstElement() prefer_timestamp_ntz = is_timestamp_ntz_preferred() if samplingRatio is None: schema = _infer_schema( first, names=names, infer_dict_as_struct=infer_dict_as_struct, prefer_timestamp_ntz=prefer_timestamp_ntz, ) if _has_nulltype(schema): for row in rdd.take(100)[1:]: schema = _merge_type( schema, _infer_schema( row, names=names, infer_dict_as_struct=infer_dict_as_struct, infer_array_from_first_element=infer_array_from_first_element, prefer_timestamp_ntz=prefer_timestamp_ntz, ), ) if not _has_nulltype(schema): break else: raise ValueError( "Some of types cannot be determined by the " "first 100 rows, please try again with sampling" ) else: if samplingRatio < 0.99: rdd = rdd.sample(False, float(samplingRatio)) schema = rdd.map( lambda row: _infer_schema( row, names, infer_dict_as_struct=infer_dict_as_struct, infer_array_from_first_element=infer_array_from_first_element, prefer_timestamp_ntz=prefer_timestamp_ntz, ) ).reduce(_merge_type) return schema def _createFromRDD( self, rdd: RDD[Any], schema: Optional[Union[DataType, List[str]]], samplingRatio: Optional[float], ) -> Tuple[RDD[Tuple], StructType]: """ Create an RDD for DataFrame from an existing RDD, returns the RDD and schema. """ if schema is None or isinstance(schema, (list, tuple)): struct = self._inferSchema(rdd, samplingRatio, names=schema) converter = _create_converter(struct) tupled_rdd = rdd.map(converter) if isinstance(schema, (list, tuple)): for i, name in enumerate(schema): struct.fields[i].name = name struct.names[i] = name elif isinstance(schema, StructType): struct = schema tupled_rdd = rdd else: raise TypeError("schema should be StructType or list or None, but got: %s" % schema) # convert python objects to sql data internal_rdd = tupled_rdd.map(struct.toInternal) return internal_rdd, struct def _createFromLocal( self, data: Iterable[Any], schema: Optional[Union[DataType, List[str]]] ) -> Tuple[RDD[Tuple], StructType]: """ Create an RDD for DataFrame from a list or pandas.DataFrame, returns the RDD and schema. """ # make sure data could consumed multiple times if not isinstance(data, list): data = list(data) if schema is None or isinstance(schema, (list, tuple)): struct = self._inferSchemaFromList(data, names=schema) converter = _create_converter(struct) tupled_data: Iterable[Tuple] = map(converter, data) if isinstance(schema, (list, tuple)): for i, name in enumerate(schema): struct.fields[i].name = name struct.names[i] = name elif isinstance(schema, StructType): struct = schema tupled_data = data else: raise TypeError("schema should be StructType or list or None, but got: %s" % schema) # convert python objects to sql data internal_data = [struct.toInternal(row) for row in tupled_data] return self._sc.parallelize(internal_data), struct @staticmethod def _create_shell_session() -> "SparkSession": """ Initialize a :class:`SparkSession` for a pyspark shell session. This is called from shell.py to make error handling simpler without needing to declare local variables in that script, which would expose those to users. """ import py4j from pyspark.conf import SparkConf from pyspark.context import SparkContext try: # Try to access HiveConf, it will raise exception if Hive is not added conf = SparkConf() assert SparkContext._jvm is not None if conf.get("spark.sql.catalogImplementation", "hive").lower() == "hive": SparkContext._jvm.org.apache.hadoop.hive.conf.HiveConf() return SparkSession.builder.enableHiveSupport().getOrCreate() else: return SparkSession._getActiveSessionOrCreate() except (py4j.protocol.Py4JError, TypeError): if conf.get("spark.sql.catalogImplementation", "").lower() == "hive": warnings.warn( "Fall back to non-hive support because failing to access HiveConf, " "please make sure you build spark with hive" ) return SparkSession._getActiveSessionOrCreate() @staticmethod def _getActiveSessionOrCreate(**static_conf: Any) -> "SparkSession": """ Returns the active :class:`SparkSession` for the current thread, returned by the builder, or if there is no existing one, creates a new one based on the options set in the builder. NOTE that 'static_conf' might not be set if there's an active or default Spark session running. """ spark = SparkSession.getActiveSession() if spark is None: builder = SparkSession.builder for k, v in static_conf.items(): builder = builder.config(k, v) spark = builder.getOrCreate() return spark @overload def createDataFrame( self, data: Iterable["RowLike"], schema: Union[List[str], Tuple[str, ...]] = ..., samplingRatio: Optional[float] = ..., ) -> DataFrame: ... @overload def createDataFrame( self, data: "RDD[RowLike]", schema: Union[List[str], Tuple[str, ...]] = ..., samplingRatio: Optional[float] = ..., ) -> DataFrame: ... @overload def createDataFrame( self, data: Iterable["RowLike"], schema: Union[StructType, str], *, verifySchema: bool = ..., ) -> DataFrame: ... @overload def createDataFrame( self, data: "RDD[RowLike]", schema: Union[StructType, str], *, verifySchema: bool = ..., ) -> DataFrame: ... @overload def createDataFrame( self, data: "RDD[AtomicValue]", schema: Union[AtomicType, str], verifySchema: bool = ..., ) -> DataFrame: ... @overload def createDataFrame( self, data: Iterable["AtomicValue"], schema: Union[AtomicType, str], verifySchema: bool = ..., ) -> DataFrame: ... @overload def createDataFrame( self, data: "PandasDataFrameLike", samplingRatio: Optional[float] = ... ) -> DataFrame: ... @overload def createDataFrame( self, data: "PandasDataFrameLike", schema: Union[StructType, str], verifySchema: bool = ..., ) -> DataFrame: ...
[docs] def createDataFrame( # type: ignore[misc] self, data: Union[RDD[Any], Iterable[Any], "PandasDataFrameLike", "ArrayLike"], schema: Optional[Union[AtomicType, StructType, str]] = None, samplingRatio: Optional[float] = None, verifySchema: bool = True, ) -> DataFrame: """ Creates a :class:`DataFrame` from an :class:`RDD`, a list, a :class:`pandas.DataFrame` or a :class:`numpy.ndarray`. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Parameters ---------- data : :class:`RDD` or iterable an RDD of any kind of SQL data representation (:class:`Row`, :class:`tuple`, ``int``, ``boolean``, etc.), or :class:`list`, :class:`pandas.DataFrame` or :class:`numpy.ndarray`. schema : :class:`pyspark.sql.types.DataType`, str or list, optional a :class:`pyspark.sql.types.DataType` or a datatype string or a list of column names, default is None. The data type string format equals to :class:`pyspark.sql.types.DataType.simpleString`, except that top level struct type can omit the ``struct<>``. When ``schema`` is a list of column names, the type of each column will be inferred from ``data``. When ``schema`` is ``None``, it will try to infer the schema (column names and types) from ``data``, which should be an RDD of either :class:`Row`, :class:`namedtuple`, or :class:`dict`. When ``schema`` is :class:`pyspark.sql.types.DataType` or a datatype string, it must match the real data, or an exception will be thrown at runtime. If the given schema is not :class:`pyspark.sql.types.StructType`, it will be wrapped into a :class:`pyspark.sql.types.StructType` as its only field, and the field name will be "value". Each record will also be wrapped into a tuple, which can be converted to row later. samplingRatio : float, optional the sample ratio of rows used for inferring. The first few rows will be used if ``samplingRatio`` is ``None``. verifySchema : bool, optional verify data types of every row against schema. Enabled by default. .. versionadded:: 2.1.0 Returns ------- :class:`DataFrame` Notes ----- Usage with `spark.sql.execution.arrow.pyspark.enabled=True` is experimental. Examples -------- Create a DataFrame from a list of tuples. >>> spark.createDataFrame([('Alice', 1)]).collect() [Row(_1='Alice', _2=1)] >>> spark.createDataFrame([('Alice', 1)], ['name', 'age']).collect() [Row(name='Alice', age=1)] Create a DataFrame from a list of dictionaries >>> d = [{'name': 'Alice', 'age': 1}] >>> spark.createDataFrame(d).collect() [Row(age=1, name='Alice')] Create a DataFrame from an RDD. >>> rdd = spark.sparkContext.parallelize([('Alice', 1)]) >>> spark.createDataFrame(rdd).collect() [Row(_1='Alice', _2=1)] >>> df = spark.createDataFrame(rdd, ['name', 'age']) >>> df.collect() [Row(name='Alice', age=1)] Create a DataFrame from Row instances. >>> from pyspark.sql import Row >>> Person = Row('name', 'age') >>> person = rdd.map(lambda r: Person(*r)) >>> df2 = spark.createDataFrame(person) >>> df2.collect() [Row(name='Alice', age=1)] Create a DataFrame with the explicit schema specified. >>> from pyspark.sql.types import * >>> schema = StructType([ ... StructField("name", StringType(), True), ... StructField("age", IntegerType(), True)]) >>> df3 = spark.createDataFrame(rdd, schema) >>> df3.collect() [Row(name='Alice', age=1)] Create a DataFrame from a pandas DataFrame. >>> spark.createDataFrame(df.toPandas()).collect() # doctest: +SKIP [Row(name='Alice', age=1)] >>> spark.createDataFrame(pandas.DataFrame([[1, 2]])).collect() # doctest: +SKIP [Row(0=1, 1=2)] Create a DataFrame from an RDD with the schema in DDL formatted string. >>> spark.createDataFrame(rdd, "a: string, b: int").collect() [Row(a='Alice', b=1)] >>> rdd = rdd.map(lambda row: row[1]) >>> spark.createDataFrame(rdd, "int").collect() [Row(value=1)] When the type is unmatched, it throws an exception. >>> spark.createDataFrame(rdd, "boolean").collect() # doctest: +IGNORE_EXCEPTION_DETAIL Traceback (most recent call last): ... Py4JJavaError: ... """ SparkSession._activeSession = self assert self._jvm is not None self._jvm.SparkSession.setActiveSession(self._jsparkSession) if isinstance(data, DataFrame): raise TypeError("data is already a DataFrame") if isinstance(schema, str): schema = cast(Union[AtomicType, StructType, str], _parse_datatype_string(schema)) elif isinstance(schema, (list, tuple)): # Must re-encode any unicode strings to be consistent with StructField names schema = [x.encode("utf-8") if not isinstance(x, str) else x for x in schema] try: import pandas as pd has_pandas = True except Exception: has_pandas = False try: import numpy as np has_numpy = True except Exception: has_numpy = False if has_numpy and isinstance(data, np.ndarray): # `data` of numpy.ndarray type will be converted to a pandas DataFrame, # so pandas is required. from pyspark.sql.pandas.utils import require_minimum_pandas_version require_minimum_pandas_version() if data.ndim not in [1, 2]: raise ValueError("NumPy array input should be of 1 or 2 dimensions.") if data.ndim == 1 or data.shape[1] == 1: column_names = ["value"] else: column_names = ["_%s" % i for i in range(1, data.shape[1] + 1)] if schema is None and not self._jconf.arrowPySparkEnabled(): # Construct `schema` from `np.dtype` of the input NumPy array # TODO: Apply the logic below when self._jconf.arrowPySparkEnabled() is True spark_type = _from_numpy_type(data.dtype) if spark_type is not None: schema = StructType( [StructField(name, spark_type, nullable=True) for name in column_names] ) data = pd.DataFrame(data, columns=column_names) if has_pandas and isinstance(data, pd.DataFrame): # Create a DataFrame from pandas DataFrame. return super(SparkSession, self).createDataFrame( # type: ignore[call-overload] data, schema, samplingRatio, verifySchema ) return self._create_dataframe( data, schema, samplingRatio, verifySchema # type: ignore[arg-type] )
def _create_dataframe( self, data: Union[RDD[Any], Iterable[Any]], schema: Optional[Union[DataType, List[str]]], samplingRatio: Optional[float], verifySchema: bool, ) -> DataFrame: if isinstance(schema, StructType): verify_func = _make_type_verifier(schema) if verifySchema else lambda _: True @no_type_check def prepare(obj): verify_func(obj) return obj elif isinstance(schema, DataType): dataType = schema schema = StructType().add("value", schema) verify_func = ( _make_type_verifier(dataType, name="field value") if verifySchema else lambda _: True ) @no_type_check def prepare(obj): verify_func(obj) return (obj,) else: def prepare(obj: Any) -> Any: return obj if isinstance(data, RDD): rdd, struct = self._createFromRDD(data.map(prepare), schema, samplingRatio) else: rdd, struct = self._createFromLocal(map(prepare, data), schema) assert self._jvm is not None jrdd = self._jvm.SerDeUtil.toJavaArray(rdd._to_java_object_rdd()) jdf = self._jsparkSession.applySchemaToPythonRDD(jrdd.rdd(), struct.json()) df = DataFrame(jdf, self) df._schema = struct return df
[docs] def sql(self, sqlQuery: str, args: Optional[Dict[str, Any]] = None, **kwargs: Any) -> DataFrame: """Returns a :class:`DataFrame` representing the result of the given query. When ``kwargs`` is specified, this method formats the given string by using the Python standard formatter. The method binds named parameters to SQL literals from `args`. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect and parameterized SQL. Parameters ---------- sqlQuery : str SQL query string. args : dict A dictionary of parameter names to Python objects that can be converted to SQL literal expressions. See <a href="https://spark.apache.org/docs/latest/sql-ref-datatypes.html"> Supported Data Types</a> for supported value types in Python. For example, dictionary keys: "rank", "name", "birthdate"; dictionary values: 1, "Steven", datetime.date(2023, 4, 2). Map value can be also a `Column` of literal expression, in that case it is taken as is. .. versionadded:: 3.4.0 kwargs : dict Other variables that the user wants to set that can be referenced in the query .. versionchanged:: 3.3.0 Added optional argument ``kwargs`` to specify the mapping of variables in the query. This feature is experimental and unstable. Returns ------- :class:`DataFrame` Examples -------- Executing a SQL query. >>> spark.sql("SELECT * FROM range(10) where id > 7").show() +---+ | id| +---+ | 8| | 9| +---+ Executing a SQL query with variables as Python formatter standard. >>> spark.sql( ... "SELECT * FROM range(10) WHERE id > {bound1} AND id < {bound2}", bound1=7, bound2=9 ... ).show() +---+ | id| +---+ | 8| +---+ >>> mydf = spark.range(10) >>> spark.sql( ... "SELECT {col} FROM {mydf} WHERE id IN {x}", ... col=mydf.id, mydf=mydf, x=tuple(range(4))).show() +---+ | id| +---+ | 0| | 1| | 2| | 3| +---+ >>> spark.sql(''' ... SELECT m1.a, m2.b ... FROM {table1} m1 INNER JOIN {table2} m2 ... ON m1.key = m2.key ... ORDER BY m1.a, m2.b''', ... table1=spark.createDataFrame([(1, "a"), (2, "b")], ["a", "key"]), ... table2=spark.createDataFrame([(3, "a"), (4, "b"), (5, "b")], ["b", "key"])).show() +---+---+ | a| b| +---+---+ | 1| 3| | 2| 4| | 2| 5| +---+---+ Also, it is possible to query using class:`Column` from :class:`DataFrame`. >>> mydf = spark.createDataFrame([(1, 4), (2, 4), (3, 6)], ["A", "B"]) >>> spark.sql("SELECT {df.A}, {df[B]} FROM {df}", df=mydf).show() +---+---+ | A| B| +---+---+ | 1| 4| | 2| 4| | 3| 6| +---+---+ And substitude named parameters with the `:` prefix by SQL literals. >>> spark.sql("SELECT * FROM {df} WHERE {df[B]} > :minB", {"minB" : 5}, df=mydf).show() +---+---+ | A| B| +---+---+ | 3| 6| +---+---+ """ formatter = SQLStringFormatter(self) if len(kwargs) > 0: sqlQuery = formatter.format(sqlQuery, **kwargs) try: litArgs = {k: _to_java_column(lit(v)) for k, v in (args or {}).items()} return DataFrame(self._jsparkSession.sql(sqlQuery, litArgs), self) finally: if len(kwargs) > 0: formatter.clear()
[docs] def table(self, tableName: str) -> DataFrame: """Returns the specified table as a :class:`DataFrame`. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Parameters ---------- tableName : str the table name to retrieve. Returns ------- :class:`DataFrame` Examples -------- >>> spark.range(5).createOrReplaceTempView("table1") >>> spark.table("table1").sort("id").show() +---+ | id| +---+ | 0| | 1| | 2| | 3| | 4| +---+ """ return DataFrame(self._jsparkSession.table(tableName), self)
@property def read(self) -> DataFrameReader: """ Returns a :class:`DataFrameReader` that can be used to read data in as a :class:`DataFrame`. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Returns ------- :class:`DataFrameReader` Examples -------- >>> spark.read <...DataFrameReader object ...> Write a DataFrame into a JSON file and read it back. >>> import tempfile >>> with tempfile.TemporaryDirectory() as d: ... # Write a DataFrame into a JSON file ... spark.createDataFrame( ... [{"age": 100, "name": "Hyukjin Kwon"}] ... ).write.mode("overwrite").format("json").save(d) ... ... # Read the JSON file as a DataFrame. ... spark.read.format('json').load(d).show() +---+------------+ |age| name| +---+------------+ |100|Hyukjin Kwon| +---+------------+ """ return DataFrameReader(self) @property def readStream(self) -> DataStreamReader: """ Returns a :class:`DataStreamReader` that can be used to read data streams as a streaming :class:`DataFrame`. .. versionadded:: 2.0.0 Notes ----- This API is evolving. Returns ------- :class:`DataStreamReader` Examples -------- >>> spark.readStream <pyspark.sql.streaming.readwriter.DataStreamReader object ...> The example below uses Rate source that generates rows continuously. After that, we operate a modulo by 3, and then write the stream out to the console. The streaming query stops in 3 seconds. >>> import time >>> df = spark.readStream.format("rate").load() >>> df = df.selectExpr("value % 3 as v") >>> q = df.writeStream.format("console").start() >>> time.sleep(3) >>> q.stop() """ return DataStreamReader(self) @property def streams(self) -> "StreamingQueryManager": """Returns a :class:`StreamingQueryManager` that allows managing all the :class:`StreamingQuery` instances active on `this` context. .. versionadded:: 2.0.0 Notes ----- This API is evolving. Returns ------- :class:`StreamingQueryManager` Examples -------- >>> spark.streams <pyspark.sql.streaming.query.StreamingQueryManager object ...> Get the list of active streaming queries >>> sq = spark.readStream.format( ... "rate").load().writeStream.format('memory').queryName('this_query').start() >>> sqm = spark.streams >>> [q.name for q in sqm.active] ['this_query'] >>> sq.stop() """ from pyspark.sql.streaming import StreamingQueryManager return StreamingQueryManager(self._jsparkSession.streams())
[docs] def stop(self) -> None: """ Stop the underlying :class:`SparkContext`. .. versionadded:: 2.0.0 .. versionchanged:: 3.4.0 Supports Spark Connect. Examples -------- >>> spark.stop() # doctest: +SKIP """ from pyspark.sql.context import SQLContext self._sc.stop() # We should clean the default session up. See SPARK-23228. assert self._jvm is not None self._jvm.SparkSession.clearDefaultSession() self._jvm.SparkSession.clearActiveSession() SparkSession._instantiatedSession = None SparkSession._activeSession = None SQLContext._instantiatedContext = None
def __enter__(self) -> "SparkSession": """ Enable 'with SparkSession.builder.(...).getOrCreate() as session: app' syntax. .. versionadded:: 2.0.0 Examples -------- >>> with SparkSession.builder.master("local").getOrCreate() as session: ... session.range(5).show() # doctest: +SKIP +---+ | id| +---+ | 0| | 1| | 2| | 3| | 4| +---+ """ return self def __exit__( self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType], ) -> None: """ Enable 'with SparkSession.builder.(...).getOrCreate() as session: app' syntax. Specifically stop the SparkSession on exit of the with block. .. versionadded:: 2.0.0 Examples -------- >>> with SparkSession.builder.master("local").getOrCreate() as session: ... session.range(5).show() # doctest: +SKIP +---+ | id| +---+ | 0| | 1| | 2| | 3| | 4| +---+ """ self.stop()
def _test() -> None: import os import doctest import pyspark.sql.session os.chdir(os.environ["SPARK_HOME"]) globs = pyspark.sql.session.__dict__.copy() globs["spark"] = ( SparkSession.builder.master("local[4]").appName("sql.session tests").getOrCreate() ) (failure_count, test_count) = doctest.testmod( pyspark.sql.session, globs=globs, optionflags=doctest.ELLIPSIS | doctest.NORMALIZE_WHITESPACE, ) globs["spark"].stop() if failure_count: sys.exit(-1) if __name__ == "__main__": _test()