Python merge all child list into parent list and remove duplicates

Question

I have a huge list of lists. I want to Merge all child lists to parent list and remove duplicates item from parent list after merge.

What is the optimized wa

Answer 1

Use set and chain:

x = [['a', 'b', 'c', 2, 4], ['x', 1, 2, 3, 'z'], ['z', 'b', 'y', 'a' 'x']]

from itertools import chain

result = list(set(chain.from_iterable(x)))
print(result)