Индексация во вложенных списках

>>> list1 = [10, 20, [300, 400, [5000, 6000, 7000], 500], 30, 40]
>>> list1[2][2][0]
5000
>>> list1[2]
[300, 400, [5000, 6000, 7000], 500]
>>> list1[2][2]
[5000, 6000, 7000]
>>> list1[2][2][0]
5000

list1 = [10, 20, [300, 400, [5000, 6000, 7000], 500], 30, 40]
for i in list1:
    if type(i) == list:
        for j in i:
            if type(j) == list:
                for k in j:
                    print(j.index(k), k, sep = ' __')
            print(i.index(j), j, sep = ' _')
    print(list1.index(i), i)

def print_arr(arr, name='arr'):
    if type(arr) != list:
        print(f'{name} = {arr}')
    else:
        for i in range(len(arr)):
            print_arr(arr[i], f'{name}[{i}]')
 
arr = [10, 20, [300, 400, [5000, [60000, [[7000000, 8000000], 800000], 80000], 7000], 500], 30, 40]
print(f'arr = {arr}')
print_arr(arr)

arr = [10, 20, [300, 400, [5000, [60000, [[7000000, 8000000], 800000], 80000], 7000], 500], 30, 40]
arr[0] = 10
arr[1] = 20
arr[2][0] = 300
arr[2][1] = 400
arr[2][2][0] = 5000
arr[2][2][1][0] = 60000
arr[2][2][1][1][0][0] = 7000000
arr[2][2][1][1][0][1] = 8000000
arr[2][2][1][1][1] = 800000
arr[2][2][1][2] = 80000
arr[2][2][2] = 7000
arr[2][3] = 500
arr[3] = 30
arr[4] = 40