Error: int object does not support item assignment

[ichabod801]

As the error says, L is an integer. On line 12 you set it as an integer by using it as the loop variable in the for loop. Then on line 17 when you try to index it, you get the error. You can't index integers, only containers.

It's not clear what you expect L to be. It's not defined previously in the code you posted, but your error indicates there's a lot of code you didn't post. If you previously defined it to be something else, change the name of your loop variable on line 12.