Adding number at specific position in matrix

Question

Please refer this link for code

It is not working, saying 'List index out of range' I am a beginner, is there correct use of the function or not? Is there any way to correct the solution or do we need to find another solution? Thank you!

Answer 1

If you just want to change an element use

final_row[row - 1][column - 1] = your number here

You can also check if the row already exists or if you have to create it

if (len(final) < row) #Check if row exists
   final_row[row - 1][column - 1] = 0
else:
   final_row.append([1,1,1]) #append a row
   final_row[row - 1][column - 1] = 0