I have a variable with n words, separated by whitespaces. str.split() returns a list of these words, which is then converted to a tuple with tuple(), which is finally converted to a frozenset and added to the set of frozensets. For some reason this returns:

TypeError: 'builtin_function_or_method' object is not subscriptable

my code:

set = set([])
str = 'a b c d'
set.add[frozenset(tuple(set.split()))]

problems already addressed :

1. tried to make a set of sets`
2. tried to make a frozenset out of lists
3. accidentally used .append instead of .add

(Btw this is my first question on stack overflow)