TypeError: list indices must be integers, not list. How to fix?

Question

There\'s the code with the TypeError in it. \"list indices must be integers, not list\", though they are integers. I\'d appreciate you helping me figure out what\'s wrong.

Answer 1

i and j are not indices; they are values from the lines list. Python for loops are for-each constructs.

Use:

for i, line in enumerate(lines):
    for j, value in enumerate(line):
        T[i][j] = value + max(T[i][j - 1 % len(T[i])] + T[i - 1 % len(T)][j])

where the % len() calculations 'wrap around' to the last entry in T or T[i] when i and / or j are 0. The enumerate() function adds indices to the loop.

This does assume you already pre-built a nested list of lists structure in T.