When I use = operator in python, python creates an object for me (if it doesn't exist), and then links my variable to it. So >>>a = 1 >>>b = a >>>a = 2 >>>print(f'{a}, {b}') 2, 1 seem to be ok. For mutable objects, when I change an object, pointers still point to the same object, so this is ok too: >>>a = [] >>>b = a >>>a = a.append(1) >>>print(f'{a}, {b}') [1], [1] Now what if I will do that thing: >>>a = [1] >>>a[0] = a >>>print(f'{a}') what I was expecting is infinite links so this should provide some error, but python handling it normally, describing a as [[...]]. Now I can access object of any deepness a[0][0][0][0][0] and it still would be [[...]]. Actually [1] should be somewhere in memory, but I'm unable to access it. Okay, what will happen if I would make this thing now: >>>a[0][0][0] = 5 I would expect that a becomes either [[[5]]] or it will become 5 by itself (strange but I could say it has some sense). Actually, no. a becomes [5]. Could anyone explain why? How does it work? Continue reading...
