Splitting A List Into Two Seperate Lists, By Every Other Item In Python

Hello I have a quick question I cant seem to solve. I have a list: a = [item1, item2, item3, item4, item5, item6] And I want to split this list into two seperate ones by everythin

Solution 1:

Use slicing, specifying a step:

b,c= a[::2], a[1::2]

Solution 2:

Using filter is one option:

a = [item1, item2, item3, item4, item5, item6]
b = filter(lambda x: a.index(x) % 2 == 0, a)
c = filter(lambda x: a.index(x) % 2 != 0, a)

EDIT: This would require for the elements to be unique and is inefficient.