Its because the length of the printed array when on one line is less than the default width
of 80. You might want to review the documentation for pprint
.
For example, if we do:
matrix = [ [1,2,3], [4,5,6], [7,8,9] ]
import pprint
pp = pprint.PrettyPrinter(indent=4,width=20)
pp.pprint(matrix)
We get:
[ [1, 2, 3],
[4, 5, 6],
[7, 8, 9]]