StaySteady

index = [
    ["group_01", [ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10]],
    ["group_02", [ 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]],
    ["group_03", [ 21, 22, 23, 24, 25, 26, 27, 28, 29, 30]]]
    
for i, Grouping in enumerate(index):
    print("i:",i,"Grouping : ", Grouping)

i: 0 Grouping : ['group_01', [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]]

i: 1 Grouping : ['group_02', [11, 12, 13, 14, 15, 16, 17, 18, 19, 20]]

i: 2 Grouping : ['group_03', [21, 22, 23, 24, 25, 26, 27, 28, 29, 30]]