I have a data frame like below
col1
-----------------
[a1_b1_c1, a2_b2_c2, a3_b3_c3]
[aa1_bb1_cc1, aa2_bb2_cc2, aa3_bb3]
[aaa2_bbb2_ccc1, aaa2_bbb2_cc2, aaa3_bbb3]
now I want to split the elements, need to form the below-mentioned data frame,
newcol1
--------
[c1,c2,c3]
[cc1,cc2,null]
[ccc1,ccc2,null]
Please suggest to me the best way to achieve this?