slicing the end of a string in a list

[John Salerno]

Steven D'Aprano wrote:

> The important term there is BINARY, not large. Many problems *reading*
> (not opening) binary files will go away if you use 'rb', regardless of
> whether they are small, medium or large.

Is 'b' the proper parameter to use when you want to read/write a binary 
file? I was wondering about this, because the book I'm reading doesn't 
talk about dealing with binary files.