Should mach_o package use bytes strings?

[YngveNPettersen]

I have just been debugging a third party script using macholib for decoding a Mac executable being read with "rb" mode, which did not work when running in Python 3.

Once the bugs in the script itself had been fixed I hit another snag where a bytes.startswith(mach_o.SEG_TEXT) operation failed with an error due to SEG_TEXT being an str string, not a bytes string.

macholib/macholib/mach_o.py

Line 802 in 0f77e70

SEG_TEXT = "__TEXT"

My guess is that this also applies to many, if not all, the strings in the file, and possibly others in the lib