Enhance tests

Author: vstinner

tests/test_pythoncapi_compat_cext.c

@@ -849,9 +849,14 @@ test_vectorcall_args_kwnames(PyObject *func_varargs)
     assert(args_tuple != NULL);
     PyObject **args = &PyTuple_GET_ITEM(args_tuple, 0);
 
+#ifdef PYTHON3
     PyObject *key1 = PyUnicode_FromString("key1");
-    assert(key1 != NULL);
     PyObject *key2 = PyUnicode_FromString("key2");
+#else
+    PyObject *key1 = PyString_FromString("key1");
+    PyObject *key2 = PyString_FromString("key2");
+#endif
+    assert(key1 != NULL);
     assert(key2 != NULL);
     PyObject *kwnames = PyTuple_Pack(2, key1, key2);
     assert(kwnames != NULL);
@@ -882,8 +887,7 @@ test_vectorcall_args_kwnames(PyObject *func_varargs)
 #ifdef PYTHON3
         assert(PyUnicode_Check(key));
 #else
-        // CPython 2.7 creates PyUnicode keys, PyPy2 creates PyString keys
-        assert(PyString_Check(key) || PyUnicode_Check(key));
+        assert(PyString_Check(key));
 #endif
         if (PyObject_RichCompareBool(key, key1, Py_EQ)) {
             check_int(value, 4);