diff options
3 files changed, 22 insertions, 2 deletions
diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py index e422363ec1..8a01805ec8 100644 --- a/python/pyspark/sql/functions.py +++ b/python/pyspark/sql/functions.py @@ -1445,6 +1445,9 @@ def regexp_extract(str, pattern, idx): >>> df = spark.createDataFrame([('100-200',)], ['str']) >>> df.select(regexp_extract('str', '(\d+)-(\d+)', 1).alias('d')).collect() [Row(d=u'100')] + >>> df = spark.createDataFrame([('aaaac',)], ['str']) + >>> df.select(regexp_extract('str', '(a+)(b)?(c)', 2).alias('d')).collect() + [Row(d=u'')] """ sc = SparkContext._active_spark_context jc = sc._jvm.functions.regexp_extract(_to_java_column(str), pattern, idx) diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/regexpExpressions.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/regexpExpressions.scala index be82b3b8f4..d25da3fd58 100644 --- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/regexpExpressions.scala +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/regexpExpressions.scala @@ -329,7 +329,12 @@ case class RegExpExtract(subject: Expression, regexp: Expression, idx: Expressio val m = pattern.matcher(s.toString) if (m.find) { val mr: MatchResult = m.toMatchResult - UTF8String.fromString(mr.group(r.asInstanceOf[Int])) + val group = mr.group(r.asInstanceOf[Int]) + if (group == null) { // Pattern matched, but not optional group + UTF8String.EMPTY_UTF8 + } else { + UTF8String.fromString(group) + } } else { UTF8String.EMPTY_UTF8 } @@ -367,7 +372,11 @@ case class RegExpExtract(subject: Expression, regexp: Expression, idx: Expressio ${termPattern}.matcher($subject.toString()); if (${matcher}.find()) { java.util.regex.MatchResult ${matchResult} = ${matcher}.toMatchResult(); - ${ev.value} = UTF8String.fromString(${matchResult}.group($idx)); + if (${matchResult}.group($idx) == null) { + ${ev.value} = UTF8String.EMPTY_UTF8; + } else { + ${ev.value} = UTF8String.fromString(${matchResult}.group($idx)); + } $setEvNotNull } else { ${ev.value} = UTF8String.EMPTY_UTF8; diff --git a/sql/core/src/test/scala/org/apache/spark/sql/StringFunctionsSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/StringFunctionsSuite.scala index 57ca5d9c4d..3b76aaf7d0 100644 --- a/sql/core/src/test/scala/org/apache/spark/sql/StringFunctionsSuite.scala +++ b/sql/core/src/test/scala/org/apache/spark/sql/StringFunctionsSuite.scala @@ -94,6 +94,14 @@ class StringFunctionsSuite extends QueryTest with SharedSQLContext { Row("300", "100") :: Row("400", "100") :: Row("400-400", "100") :: Nil) } + test("non-matching optional group") { + val df = Seq("aaaac").toDF("s") + checkAnswer( + df.select(regexp_extract($"s", "(a+)(b)?(c)", 2)), + Row("") + ) + } + test("string ascii function") { val df = Seq(("abc", "")).toDF("a", "b") checkAnswer( |