Add element on List + Showing the index of this List

Question

list1 = [10, 20, [300, 400, [5000, 6000], 500], 30, 40] 

1. i've needed to add element "7000" after the [6000]

2. also how to show the index of the value of 40

Answer 1

Use list.insert and list.index

list1 = [10, 20, [300, 400, [5000, 6000], 500], 30, 40]
print(list1)

list1[2][2].insert(2, 7000)  
print(list1)

print(list1.index(40))

[10, 20, [300, 400, [5000, 6000], 500], 30, 40]
[10, 20, [300, 400, [5000, 6000, 7000], 500], 30, 40]
4