BUG: DataFrame.to_json OverflowError with np.long* dtypes

Author: gupta-paras

doc/source/whatsnew/v2.2.0.rst

@@ -348,6 +348,7 @@ I/O
 - Bug in :func:`read_csv` with ``engine="pyarrow"`` where ``usecols`` wasn't working with a csv with no headers (:issue:`54459`)
 - Bug in :func:`read_excel`, with ``engine="xlrd"`` (``xls`` files) erroring when file contains NaNs/Infs (:issue:`54564`)
 - Bug in :func:`to_excel`, with ``OdsWriter`` (``ods`` files) writing boolean/string value (:issue:`54994`)
+- Bug in :meth:`DataFrame.to_json` OverflowError with np.long* dtypes (:issue:`55403`)
 - Bug in :meth:`pandas.read_excel` with an ODS file without cached formatted cell for float values (:issue:`55219`)
 
 Period

pandas/_libs/src/vendored/ujson/python/objToJSON.c

@@ -1610,6 +1610,11 @@ void Object_beginTypeContext(JSOBJ _obj, JSONTypeContext *tc) {
                                   PyArray_DescrFromType(NPY_DOUBLE));
         tc->type = JT_DOUBLE;
         return;
+    } else if (PyArray_IsScalar(obj, LongDouble)) {
+        PyErr_Format(PyExc_TypeError,
+                     "%R (np.longdouble) is not JSON serializable at the moment",
+                     obj);
+        goto INVALID;
     } else if (PyArray_Check(obj) && PyArray_CheckScalar(obj)) {
         PyErr_Format(PyExc_TypeError,
                      "%R (0d array) is not JSON serializable at the moment",

pandas/tests/io/json/test_ujson.py

@@ -818,6 +818,11 @@ def test_0d_array(self):
         with pytest.raises(TypeError, match=msg):
             ujson.ujson_dumps(np.array(1))
 
+    def test_array_long_double(self):
+        msg = re.escape("1.0 (np.longdouble) is not JSON serializable at the moment")
+        with pytest.raises(TypeError, match=msg):
+            ujson.ujson_dumps(np.longdouble(1))
+
 
 class TestPandasJSONTests:
     def test_dataframe(self, orient):