Yes like this:
defaultdict(lambda: defaultdict(int))
The argument of a defaultdict
(in this case is lambda: defaultdict(int)
) will be called when you try to access a key that doesn’t exist. The return value of it will be set as the new value of this key, which means in our case the value of d[Key_doesnt_exist]
will be defaultdict(int)
.
If you try to access a key from this last defaultdict i.e. d[Key_doesnt_exist][Key_doesnt_exist]
it will return 0, which is the return value of the argument of the last defaultdict i.e. int()
.