J
jimbo1qaz
spots[y][x]=mark fails with a "'str' object does not support item assignment" error,even though:
Spots is a nested list created as a copy of another list.
both work.a=[["a"]]
a[0][0]="b" and:
a=[["a"]]
a[0][0]=1000000
Spots is a nested list created as a copy of another list.