add __delitem__() funtion

Author: CHOUMnote

extra_tests/snippets/builtin_memoryview.py

@@ -69,3 +69,17 @@ def test_resizable():
     b.append(7)
 
 test_resizable()
+
+def test_delitem():
+    a = b'abc'
+    b = memoryview(a)
+    assert_raises(TypeError, lambda : b.__delitem__())
+    assert_raises(TypeError, lambda : b.__delitem__(0))
+    assert_raises(TypeError, lambda : b.__delitem__(10))
+    a = bytearray(b'abc')
+    b = memoryview(a)
+    assert_raises(TypeError, lambda : b.__delitem__())
+    assert_raises(TypeError, lambda : b.__delitem__(1))
+    assert_raises(TypeError, lambda : b.__delitem__(12))
+
+test_delitem()

vm/src/builtins/memory.rs

@@ -362,6 +362,14 @@ impl PyMemoryView {
         self.pack_single(pos, value, vm)
     }
 
+    #[pymethod(magic)]
+    fn delitem(&self, _needle: PyObjectRef, vm: &VirtualMachine) -> PyResult<()> {
+        if self.desc.readonly {
+            return Err(vm.new_type_error("cannot modify read-only memory".to_owned()));
+        }
+        Err(vm.new_type_error("cannot delete memory".to_owned()))
+    }
+
     #[pymethod(magic)]
     fn setitem(
         zelf: PyRef<Self>,