[SPARK-23736][SQL] Fixing Python test

Author: mn-mikke

python/pyspark/sql/functions.py

@@ -2098,6 +2098,7 @@ def sort_array(col, asc=True):
 
 
 @since(1.5)
+@ignore_unicode_prefix
 def reverse(col):
     """
     Collection function: returns a reversed string or an array with reverse order of elements.

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/CollectionExpressionsSuite.scala

@@ -107,7 +107,7 @@ class CollectionExpressionsSuite extends SparkFunSuite with ExpressionEvalHelper
   }
 
   test("Reverse") {
-    // Simple-type elements
+    // Primitive-type elements
     val ai0 = Literal.create(Seq(2, 1, 4, 3), ArrayType(IntegerType))
     val ai1 = Literal.create(Seq(2, 1, 3), ArrayType(IntegerType))
     val ai2 = Literal.create(Seq(null, 1, null, 3), ArrayType(IntegerType))
@@ -126,7 +126,7 @@ class CollectionExpressionsSuite extends SparkFunSuite with ExpressionEvalHelper
     checkEvaluation(Reverse(ai6), Seq.empty)
     checkEvaluation(Reverse(ai7), null)
 
-    // Complex-type elements
+    // Non-primitive-type elements
     val as0 = Literal.create(Seq("b", "a", "d", "c"), ArrayType(StringType))
     val as1 = Literal.create(Seq("b", "a", "c"), ArrayType(StringType))
     val as2 = Literal.create(Seq(null, "a", null, "c"), ArrayType(StringType))

sql/core/src/test/scala/org/apache/spark/sql/DataFrameFunctionsSuite.scala

@@ -469,7 +469,7 @@ class DataFrameFunctionsSuite extends QueryTest with SharedSQLContext {
       Seq(Row(Seq(null, 2, null, 1)))
     )
 
-    // Array test cases (complex-type elements)
+    // Array test cases (non-primitive-type elements)
     val sdf = Seq(
       Seq("c", "a", "b"),
       Seq("b", null, "c", null),