python - Identifying sublists entirely contained within other lists -

i find sublist within list matches list, , create new list:

so this:

lista = [["a", "b", "c"],["d", "e", "f"]] listb = ["b", "c", "d", "e", "f"] 

to generate this:

newvariable = ["d", "e", "f"] 

because a, b, c not contained in listb, d, e, f is.

i have tried loops all() can't seem make them work?

any ideas? i'm guessing simple i'm missing.

the straight forward solution

>>> lista = [["a", "b", "c"],["d", "e", "f"]] >>> listb = ["b", "c", "d", "e", "f"] >>> set_b = set(listb) >>>  >>> [l l in lista if all(x in set_b x in l)] [['d', 'e', 'f']] 

which gives list lists lista contained in listb.

note instead of using listb actual containment checks using set set_b sets have o(1) membership checks. (otherwise, above all-checks have quadratic runtime.)

i assumed order of elements in listb not matter. if does, please clarify.