>>> a = object() >>> a.x = 5 Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'object' object has no attribute 'x' >>> b = lambda:0 >>> b.x = 5 >>> b.x 5 Why do instances of the object class not have a __dict__, causing it to behave as semantically immutable? What were the reasons for choosing this design? Specifically, why: instances of types defined in C don't have a __dict__ attribute by default. As noted in this question. Continue reading...
