diff --git a/py/objtype.c b/py/objtype.c index 236c79e6ad..bf089dc490 100644 --- a/py/objtype.c +++ b/py/objtype.c @@ -1014,6 +1014,21 @@ STATIC void type_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) { dest[0] = MP_OBJ_NEW_QSTR(self->name); return; } + if (attr == MP_QSTR___bases__) { + if (self == &mp_type_object) { + dest[0] = mp_const_empty_tuple; + return; + } + mp_obj_t parent_obj = self->parent ? MP_OBJ_FROM_PTR(self->parent) : MP_OBJ_FROM_PTR(&mp_type_object); + #if MICROPY_MULTIPLE_INHERITANCE + if (mp_obj_is_type(parent_obj, &mp_type_tuple)) { + dest[0] = parent_obj; + return; + } + #endif + dest[0] = mp_obj_new_tuple(1, &parent_obj); + return; + } #endif struct class_lookup_data lookup = { .obj = (mp_obj_instance_t*)self, diff --git a/tests/basics/class_bases.py b/tests/basics/class_bases.py new file mode 100644 index 0000000000..d3cf4f598a --- /dev/null +++ b/tests/basics/class_bases.py @@ -0,0 +1,45 @@ +# test for type.__bases__ implementation + +if not hasattr(object, '__bases__'): + print("SKIP") + raise SystemExit + +class A: + pass + +class B(object): + pass + +class C(B): + pass + +class D(C, A): + pass + +# Check the attribute exists +print(hasattr(A, '__bases__')) +print(hasattr(B, '__bases__')) +print(hasattr(C, '__bases__')) +print(hasattr(D, '__bases__')) + +# Check it is always a tuple +print(type(A.__bases__) == tuple) +print(type(B.__bases__) == tuple) +print(type(C.__bases__) == tuple) +print(type(D.__bases__) == tuple) + +# Check size +print(len(A.__bases__) == 1) +print(len(B.__bases__) == 1) +print(len(C.__bases__) == 1) +print(len(D.__bases__) == 2) + +# Check values +print(A.__bases__[0] == object) +print(B.__bases__[0] == object) +print(C.__bases__[0] == B) +print(D.__bases__[0] == C) +print(D.__bases__[1] == A) + +# Object has an empty tuple +print(object.__bases__ == tuple())