homepage

doctest.testmod() fails when attempting to echo back a bytes type with
ord() > 128.
def ok():
 """
>>> bytes([255,])
b'\xff'
"""
 pass
def notOK():
 """
>>> b'\xff'
"""
 pass
import doctest
doctest.testmod()
Traceback (most recent call last):
...
UnicodeEncodeError: 'ascii' codec can't encode character '\xff' in
position 141: ordinal not in range(128)

You've included a chr(255) character in your docstring. You need to
escape the backslash in order to include the bytes representation like
it will be generated.