Repository: spark Updated Branches: refs/heads/master 1a6815cd9 -> a853a8020
[SPARK-25666][PYTHON] Internally document type conversion between Python data and SQL types in normal UDFs ### What changes were proposed in this pull request? We are facing some problems about type conversions between Python data and SQL types in UDFs (Pandas UDFs as well). It's even difficult to identify the problems (see https://github.com/apache/spark/pull/20163 and https://github.com/apache/spark/pull/22610). This PR targets to internally document the type conversion table. Some of them looks buggy and we should fix them. ```python import sys import array import datetime from decimal import Decimal from pyspark.sql import Row from pyspark.sql.types import * from pyspark.sql.functions import udf if sys.version >= '3': long = int data = [ None, True, 1, long(1), "a", u"a", datetime.date(1970, 1, 1), datetime.datetime(1970, 1, 1, 0, 0), 1.0, array.array("i", [1]), [1], (1,), bytearray([65, 66, 67]), Decimal(1), {"a": 1}, Row(kwargs=1), Row("namedtuple")(1), ] types = [ BooleanType(), ByteType(), ShortType(), IntegerType(), LongType(), StringType(), DateType(), TimestampType(), FloatType(), DoubleType(), ArrayType(IntegerType()), BinaryType(), DecimalType(10, 0), MapType(StringType(), IntegerType()), StructType([StructField("_1", IntegerType())]), ] df = spark.range(1) results = [] count = 0 total = len(types) * len(data) spark.sparkContext.setLogLevel("FATAL") for t in types: result = [] for v in data: try: row = df.select(udf(lambda: v, t)()).first() ret_str = repr(row[0]) except Exception: ret_str = "X" result.append(ret_str) progress = "SQL Type: [%s]\n Python Value: [%s(%s)]\n Result Python Value: [%s]" % ( t.simpleString(), str(v), type(v).__name__, ret_str) count += 1 print("%s/%s:\n %s" % (count, total, progress)) results.append([t.simpleString()] + list(map(str, result))) schema = ["SQL Type \\ Python Value(Type)"] + list(map(lambda v: "%s(%s)" % (str(v), type(v).__name__), data)) strings = spark.createDataFrame(results, schema=schema)._jdf.showString(20, 20, False) print("\n".join(map(lambda line: " # %s # noqa" % line, strings.strip().split("\n")))) ``` This table was generated under Python 2 but the code above is Python 3 compatible as well. ## How was this patch tested? Manually tested and lint check. Closes #22655 from HyukjinKwon/SPARK-25666. Authored-by: hyukjinkwon <gurwls...@apache.org> Signed-off-by: hyukjinkwon <gurwls...@apache.org> Project: http://git-wip-us.apache.org/repos/asf/spark/repo Commit: http://git-wip-us.apache.org/repos/asf/spark/commit/a853a802 Tree: http://git-wip-us.apache.org/repos/asf/spark/tree/a853a802 Diff: http://git-wip-us.apache.org/repos/asf/spark/diff/a853a802 Branch: refs/heads/master Commit: a853a80202032083ad411eec5ec97b304f732a61 Parents: 1a6815c Author: hyukjinkwon <gurwls...@apache.org> Authored: Mon Oct 8 15:47:15 2018 +0800 Committer: hyukjinkwon <gurwls...@apache.org> Committed: Mon Oct 8 15:47:15 2018 +0800 ---------------------------------------------------------------------- python/pyspark/sql/functions.py | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/spark/blob/a853a802/python/pyspark/sql/functions.py ---------------------------------------------------------------------- diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py index be089ee..5425d31 100644 --- a/python/pyspark/sql/functions.py +++ b/python/pyspark/sql/functions.py @@ -2733,6 +2733,39 @@ def udf(f=None, returnType=StringType()): | 8| JOHN DOE| 22| +----------+--------------+------------+ """ + + # The following table shows most of Python data and SQL type conversions in normal UDFs that + # are not yet visible to the user. Some of behaviors are buggy and might be changed in the near + # future. The table might have to be eventually documented externally. + # Please see SPARK-25666's PR to see the codes in order to generate the table below. + # + # +-----------------------------+--------------+----------+------+-------+---------------+---------------+--------------------+-----------------------------+----------+----------------------+---------+--------------------+-----------------+------------+--------------+------------------+----------------------+ # noqa + # |SQL Type \ Python Value(Type)|None(NoneType)|True(bool)|1(int)|1(long)| a(str)| a(unicode)| 1970-01-01(date)|1970-01-01 00:00:00(datetime)|1.0(float)|array('i', [1])(array)|[1](list)| (1,)(tuple)| ABC(bytearray)| 1(Decimal)|{'a': 1}(dict)|Row(kwargs=1)(Row)|Row(namedtuple=1)(Row)| # noqa + # +-----------------------------+--------------+----------+------+-------+---------------+---------------+--------------------+-----------------------------+----------+----------------------+---------+--------------------+-----------------+------------+--------------+------------------+----------------------+ # noqa + # | boolean| None| True| None| None| None| None| None| None| None| None| None| None| None| None| None| X| X| # noqa + # | tinyint| None| None| 1| 1| None| None| None| None| None| None| None| None| None| None| None| X| X| # noqa + # | smallint| None| None| 1| 1| None| None| None| None| None| None| None| None| None| None| None| X| X| # noqa + # | int| None| None| 1| 1| None| None| None| None| None| None| None| None| None| None| None| X| X| # noqa + # | bigint| None| None| 1| 1| None| None| None| None| None| None| None| None| None| None| None| X| X| # noqa + # | string| None| u'true'| u'1'| u'1'| u'a'| u'a'|u'java.util.Grego...| u'java.util.Grego...| u'1.0'| u'[I@24a83055'| u'[1]'|u'[Ljava.lang.Obj...| u'[B@49093632'| u'1'| u'{a=1}'| X| X| # noqa + # | date| None| X| X| X| X| X|datetime.date(197...| datetime.date(197...| X| X| X| X| X| X| X| X| X| # noqa + # | timestamp| None| X| X| X| X| X| X| datetime.datetime...| X| X| X| X| X| X| X| X| X| # noqa + # | float| None| None| None| None| None| None| None| None| 1.0| None| None| None| None| None| None| X| X| # noqa + # | double| None| None| None| None| None| None| None| None| 1.0| None| None| None| None| None| None| X| X| # noqa + # | array<int>| None| None| None| None| None| None| None| None| None| [1]| [1]| [1]| [65, 66, 67]| None| None| X| X| # noqa + # | binary| None| None| None| None|bytearray(b'a')|bytearray(b'a')| None| None| None| None| None| None|bytearray(b'ABC')| None| None| X| X| # noqa + # | decimal(10,0)| None| None| None| None| None| None| None| None| None| None| None| None| None|Decimal('1')| None| X| X| # noqa + # | map<string,int>| None| None| None| None| None| None| None| None| None| None| None| None| None| None| {u'a': 1}| X| X| # noqa + # | struct<_1:int>| None| X| X| X| X| X| X| X| X| X|Row(_1=1)| Row(_1=1)| X| X| Row(_1=None)| Row(_1=1)| Row(_1=1)| # noqa + # +-----------------------------+--------------+----------+------+-------+---------------+---------------+--------------------+-----------------------------+----------+----------------------+---------+--------------------+-----------------+------------+--------------+------------------+----------------------+ # noqa + # + # Note: DDL formatted string is used for 'SQL Type' for simplicity. This string can be + # used in `returnType`. + # Note: The values inside of the table are generated by `repr`. + # Note: Python 2 is used to generate this table since it is used to check the backward + # compatibility often in practice. + # Note: 'X' means it throws an exception during the conversion. + # decorator @udf, @udf(), @udf(dataType()) if f is None or isinstance(f, (str, DataType)): # If DataType has been passed as a positional argument --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@spark.apache.org For additional commands, e-mail: commits-h...@spark.apache.org
