[SPARK-46543][PYTHON][CONNECT] Make json_tuple throw PySparkValueError for empty fields

### What changes were proposed in this pull request?
Make `json_tuple` throw PySparkValueError for empty fields

### Why are the changes needed?
Python side should have the same check as the Scala side:
https://github.com/apache/spark/blob/fa4096eb6aba4c66f0d9c5dcbabdfc0804064fff/sql/core/src/main/scala/org/apache/spark/sql/functions.scala#L6330-L6334

### Does this PR introduce _any_ user-facing change?
yes

### How was this patch tested?
added ut

### Was this patch authored or co-authored using generative AI tooling?
no

Closes #44534 from zhengruifeng/py_check_functions.

Authored-by: Ruifeng Zheng <[email protected]>
Signed-off-by: Ruifeng Zheng <[email protected]>

Author: zhengruifeng

python/pyspark/sql/connect/functions/builtin.py

@@ -1928,6 +1928,11 @@ def inline_outer(col: "ColumnOrName") -> Column:
 
 
 def json_tuple(col: "ColumnOrName", *fields: str) -> Column:
+    if len(fields) == 0:
+        raise PySparkValueError(
+            error_class="CANNOT_BE_EMPTY",
+            message_parameters={"item": "field"},
+        )
     return _invoke_function("json_tuple", _to_col(col), *[lit(field) for field in fields])
 
 

python/pyspark/sql/functions/builtin.py

@@ -14246,6 +14246,11 @@ def json_tuple(col: "ColumnOrName", *fields: str) -> Column:
     >>> df.select(df.key, json_tuple(df.jstring, 'f1', 'f2')).collect()
     [Row(key='1', c0='value1', c1='value2'), Row(key='2', c0='value12', c1=None)]
     """
+    if len(fields) == 0:
+        raise PySparkValueError(
+            error_class="CANNOT_BE_EMPTY",
+            message_parameters={"item": "field"},
+        )
     sc = _get_active_spark_context()
     return _invoke_function("json_tuple", _to_java_column(col), _to_seq(sc, fields))
 

python/pyspark/sql/tests/test_functions.py

@@ -1452,6 +1452,20 @@ def test_current_timestamp(self):
         self.assertIsInstance(df.first()[0], datetime.datetime)
         self.assertEqual(df.schema.names[0], "now()")
 
+    def test_json_tuple_empty_fields(self):
+        df = self.spark.createDataFrame(
+            [
+                ("1", """{"f1": "value1", "f2": "value2"}"""),
+                ("2", """{"f1": "value12"}"""),
+            ],
+            ("key", "jstring"),
+        )
+        self.assertRaisesRegex(
+            PySparkValueError,
+            "At least one field must be specified",
+            lambda: df.select(F.json_tuple(df.jstring)),
+        )
+
 
 class FunctionsTests(ReusedSQLTestCase, FunctionsTestsMixin):
     pass