Fix issue #1667. The _Printer() class was using sys.stdin.readline()

Fix issue #1667.  The _Printer() class was using sys.stdin.readline()
instead of input() to read the user's input (since at some point in
the past raw_input() was removed), but the code used to decode the
input wasn't changed.  Fixed it by going back to input(), which has
since been added back with the same semantics as the old raw_input().