Delete all occurrences of specific values from list of lists python

Question

As far as I can see this question (surprisingly?) has not been asked before - unless I am failing to spot an equivalent question due to lack of experience. (Similar questions h

Answer 1

I'd write a function that just takes one list (or iterable) and a set, and returns a new list with the values from the set removed:

def list_without_values(L, values):
    return [l for l in L if l not in values]

Then I'd turn list_A into a set for fast checking, and loop over the original list:

set_A = set(list_A)
list_of_lists = [list_without_values(L, set_A) for L in list_of_lists]

Should be fast enough and readibility is what matters most.

Answer 2

Using list comprehension should work as:

new_list = [[i for i in l if i not in list_A] for l in list_of_list]

After that, if you want to remove empty lists, you can make:

for i in new_list:
    if not i:
        new_list.remove(i)

of, as @ferhatelmas pointed in comments:

new_list = [i for i in new_list if i]

To avoid duplicates in list_A you can convert it to a set before with list_A = set(list_A)