Removed is_sparse_array from objToJSON (pandas-dev#30136)

Author: WillAyd

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

@@ -212,36 +212,19 @@ static TypeContext *createTypeContext(void) {
     return pc;
 }
 
-static int is_sparse_array(PyObject *obj) {
-    // TODO can be removed again once SparseArray.values is removed (GH26421)
-    if (PyObject_HasAttrString(obj, "_subtyp")) {
-        PyObject *_subtype = PyObject_GetAttrString(obj, "_subtyp");
-        PyObject *sparse_array = PyUnicode_FromString("sparse_array");
-        int ret = PyUnicode_Compare(_subtype, sparse_array);
-
-        if (ret == 0) {
-            return 1;
-        }
-    }
-    return 0;
-}
-
 static PyObject *get_values(PyObject *obj) {
     PyObject *values = NULL;
 
-    if (!is_sparse_array(obj)) {
-        values = PyObject_GetAttrString(obj, "values");
-        PRINTMARK();
-    }
+    values = PyObject_GetAttrString(obj, "values");
+    PRINTMARK();
 
     if (values && !PyArray_CheckExact(values)) {
 
         if (PyObject_HasAttrString(values, "to_numpy")) {
             values = PyObject_CallMethod(values, "to_numpy", NULL);
         }
 
-        if (!is_sparse_array(values) &&
-            PyObject_HasAttrString(values, "values")) {
+        if (PyObject_HasAttrString(values, "values")) {
             PyObject *subvals = get_values(values);
             PyErr_Clear();
             PRINTMARK();