BUG: json_normalize handles non‑string keys in meta with record_path (GH#62264)

Coerce meta path elements to str when constructing meta_keys to avoid TypeError during sep.join and align with nested_to_record behavior.

Add regression test in TestJSONNormalize to verify integer meta keys with record_path produce string-labeled columns and correct repetition.

Closes GH#62264.

Author: skalwaghe-56

pandas/io/json/_normalize.py

@@ -540,7 +540,7 @@ def _pull_records(js: dict[str, Any], spec: list | str) -> list:
     lengths = []
 
     meta_vals: DefaultDict = defaultdict(list)
-    meta_keys = [sep.join(val) for val in _meta]
+    meta_keys = [sep.join(str(v) for v in val) for val in _meta]
 
     def _recursive_extract(data, path, seen_meta, level: int = 0) -> None:
         if isinstance(data, dict):

pandas/tests/io/json/test_normalize.py

@@ -569,6 +569,23 @@ def test_series_index(self, state_data):
         result = json_normalize(series, "counties")
         tm.assert_index_equal(result.index, idx.repeat([3, 2]))
 
+    def test_json_normalize_meta_int_key_with_record_path(self):
+        # GH#62264
+        data = [{"name": "Alice", 12: 20, "purchases": [{"pid": 301}, {"pid": 302}]}]
+
+        result = json_normalize(data, record_path=["purchases"], meta=[12, "name"])
+
+        expected = DataFrame(
+            {
+                "pid": [301, 302],
+                "12": np.array([20, 20], dtype=object),
+                "name": ["Alice", "Alice"],
+            },
+            columns=["pid", "12", "name"],
+        )
+
+        tm.assert_frame_equal(result[["pid", "12", "name"]], expected)
+
 
 class TestNestedToRecord:
     def test_flat_stays_flat(self):