same way you did the fill in, but reverse the indexes:
>>> for j in range(columns):
... for i in range(rows):
... print mylist[i][j],
...
0,0 1,0 2,0 0,1 1,1 2,1
>>>
same way you did the fill in, but reverse the indexes:
>>> for j in range(columns):
... for i in range(rows):
... print mylist[i][j],
...
0,0 1,0 2,0 0,1 1,1 2,1
>>>