Reliably testing cross-platform terminal/console output

Are there any frameworks that let me reliably test the output of the terminal/console?

The problem is that if I redirect the stdout, its encoding, mode and probably other settings and capabilities are lost. The only way I see it is to do output to actual console/terminal and compare it graphically. Is there anything that could help with this task across platforms?

I am using Python and my module needs to be run on Windows, Linux, BSD, OS X and be able to output unicode characters to stdout without failing with various unicode decode errors.