pyspark.sql.SparkSession.createDataFrame¶
-
SparkSession.
createDataFrame
(data, schema=None, samplingRatio=None, verifySchema=True)[source]¶ Creates a
DataFrame
from anRDD
, a list or apandas.DataFrame
.When
schema
is a list of column names, the type of each column will be inferred fromdata
.When
schema
isNone
, it will try to infer the schema (column names and types) fromdata
, which should be an RDD of eitherRow
,namedtuple
, ordict
.When
schema
ispyspark.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 notpyspark.sql.types.StructType
, it will be wrapped into apyspark.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.If schema inference is needed,
samplingRatio
is used to determined the ratio of rows used for schema inference. The first row will be used ifsamplingRatio
isNone
.New in version 2.0.0.
Changed in version 2.1.0: Added verifySchema.
- Parameters
- data
RDD
or iterable an RDD of any kind of SQL data representation (
Row
,tuple
,int
,boolean
, etc.), orlist
, orpandas.DataFrame
.- schema
pyspark.sql.types.DataType
, str or list, optional a
pyspark.sql.types.DataType
or a datatype string or a list of column names, default is None. The data type string format equals topyspark.sql.types.DataType.simpleString
, except that top level struct type can omit thestruct<>
and atomic types usetypeName()
as their format, e.g. usebyte
instead oftinyint
forpyspark.sql.types.ByteType
. We can also useint
as a short name forpyspark.sql.types.IntegerType
.- samplingRatiofloat, optional
the sample ratio of rows used for inferring
- verifySchemabool, optional
verify data types of every row against schema. Enabled by default.
- data
- Returns
Notes
Usage with spark.sql.execution.arrow.pyspark.enabled=True is experimental.
Examples
>>> l = [('Alice', 1)] >>> spark.createDataFrame(l).collect() [Row(_1='Alice', _2=1)] >>> spark.createDataFrame(l, ['name', 'age']).collect() [Row(name='Alice', age=1)]
>>> d = [{'name': 'Alice', 'age': 1}] >>> spark.createDataFrame(d).collect() [Row(age=1, name='Alice')]
>>> rdd = sc.parallelize(l) >>> spark.createDataFrame(rdd).collect() [Row(_1='Alice', _2=1)] >>> df = spark.createDataFrame(rdd, ['name', 'age']) >>> df.collect() [Row(name='Alice', age=1)]
>>> 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)]
>>> 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)]
>>> spark.createDataFrame(df.toPandas()).collect() [Row(name='Alice', age=1)] >>> spark.createDataFrame(pandas.DataFrame([[1, 2]])).collect() [Row(0=1, 1=2)]
>>> 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)] >>> spark.createDataFrame(rdd, "boolean").collect() Traceback (most recent call last): ... Py4JJavaError: ...