Pandas get elements from a column containing list of values using index slicing

Posting minimal reproducible example

I have a dataframe say

df  
           combined
0    [0, 0, 1, 0, 0, 1, 0, 1]
1    [1, 0, 0, 0, 0, 1, 1, 0]
2             [1, 0, 0, 0, 1]

I need to create a new column where values will be only from the alternate index.

       new_column
0    [0, 1, 0, 0]
1    [1, 0, 0, 1]
2    [1, 0, 1]

This is what I tried, but this does not work

df['combined'].str[::2]

P.S : There are numerous ways in which this can be achieved I am looking for a more pandaic approach

Answer

You may need to check your cell type is list if not do ast

import ast
df['combined'] = df['combined'].apply(ast.literal_eval)
df['combined'].str[::2]