This shows that get __getattr__-code is executed even on lookup. If your __getattr__ or your property-getter have side-effects, then even the lookup will trigge

This shows that get __getattr__-code is executed even on lookup. If your __getattr__ or your property-getter have side-effects, then even the lookup will trigger them. Then even a bare statement like foo.bar can have side-effects in the foo-object.