fix py

Author: yaooqinn

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/unresolved.scala

@@ -545,28 +545,22 @@ case class UnresolvedOrdinal(ordinal: Int)
   override lazy val resolved = false
 }
 
-trait UnresolvedBinaryExpression extends BinaryExpression with Unevaluable {
-  val operator: String
+abstract class UnresolvedBinaryExpression(operator: String)
+  extends BinaryExpression with Unevaluable {
   override lazy val resolved: Boolean = false
   override def dataType: DataType = throw new UnresolvedException(this, "dataType")
   override def sql: String = s"${left.sql} $operator ${right.sql}"
 }
 
-case class UnresolvedAdd(left: Expression, right: Expression) extends UnresolvedBinaryExpression {
-  override val operator: String = "+"
+case class UnresolvedAdd(left: Expression, right: Expression)
+  extends UnresolvedBinaryExpression("+") {
 }
 
 case class UnresolvedSubtract(left: Expression, right: Expression)
-  extends UnresolvedBinaryExpression {
-  override val operator: String = "-"
-}
+  extends UnresolvedBinaryExpression("-")
 
 case class UnresolvedMultiply(left: Expression, right: Expression)
-  extends UnresolvedBinaryExpression {
-  override val operator: String = "*"
-}
+  extends UnresolvedBinaryExpression("*")
 
 case class UnresolvedDivide(left: Expression, right: Expression)
-  extends UnresolvedBinaryExpression {
-  override val operator: String = "/"
-}
+  extends UnresolvedBinaryExpression("/")

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/package.scala

@@ -23,6 +23,7 @@ import java.nio.charset.StandardCharsets.UTF_8
 import java.util.concurrent.atomic.AtomicBoolean
 
 import org.apache.spark.internal.Logging
+import org.apache.spark.sql.catalyst.analysis.UnresolvedBinaryExpression
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.types.{NumericType, StringType}
@@ -142,7 +143,10 @@ package object util extends Logging {
     "`" + name.replace("`", "``") + "`"
   }
 
-  def toPrettySQL(e: Expression): String = usePrettyExpression(e).sql
+  def toPrettySQL(e: Expression): String = e match {
+    case u: UnresolvedBinaryExpression => u.sql
+    case _ => usePrettyExpression(e).sql
+  }
 
   def escapeSingleQuotedString(str: String): String = {
     val builder = StringBuilder.newBuilder