Pickled files should *always* be used in binary mode.

The 3.0 pickle documentation states this:

"Be sure to always open pickle files created with protocols >= 1 in
binary mode. For the old ASCII-based pickle protocol 0 you can use
either text mode or binary mode as long as you stay consistent.

A pickle file written with protocol 0 in binary mode will contain lone
linefeeds as line terminators and therefore will look “funny” when
viewed in Notepad or other editors which do not support this format."


[1] http://docs.python.org/dev/3.0/library/pickle.html#usage