BUG: Fix json_normalize meta validation GH#63019

Author: nocoding03

pandas/io/json/_normalize.py

@@ -266,6 +266,28 @@ def _simple_json_normalize(
     return normalised_json_object
 
 
+def _validate_meta(meta: list) -> None:
+    """
+    Validate that meta parameter contains only strings.
+
+    Parameters
+    ----------
+    meta : list
+        The meta parameter to validate.
+
+    Raises
+    ------
+    TypeError
+        If meta contains non-string elements.
+    """
+    for item in meta:
+        if not isinstance(item, str):
+            raise TypeError(
+                "All elements in 'meta' must be strings. "
+                f"Found {type(item).__name__}: {item!r}"
+            )
+
+
 def json_normalize(
     data: dict | list[dict] | Series,
     record_path: str | list | None = None,
@@ -426,6 +448,9 @@ def json_normalize(
 
     Returns normalized data with columns prefixed with the given string.
     """
+    if meta is not None:
+        _validate_meta(meta)
+
 
     def _pull_field(
         js: dict[str, Any], spec: list | str, extract_record: bool = False

pandas/tests/io/json/test_normalize.py

@@ -903,3 +903,21 @@ def test_series_non_zero_index(self):
             index=[1, 2, 3],
         )
         tm.assert_frame_equal(result, expected)
+
+def test_json_normalize_meta_string_validation(self):
+        # GH 63019
+        data = [{"a": 1, 12: "meta_value", "nested": [{"b": 2}]}]
+
+        # Test non-string meta raises TypeError consistently
+        with pytest.raises(TypeError, match="must be strings"):
+            json_normalize(data, meta=[12])
+
+        with pytest.raises(TypeError, match="must be strings"):
+            json_normalize(data, record_path=["nested"], meta=[12])
+
+        # Test string meta works correctly
+        result1 = json_normalize(data, meta=["a"])
+        assert "a" in result1.columns
+
+        result2 = json_normalize(data, record_path=["nested"], meta=["a"])
+        assert "a" in result2.columns