Closing as not a bug.

FWIW, here's the relevant text from the docs:
---------------------------------------------
23.2.3.6 Warnings 
doctest is serious about requiring exact matches in expected output. If 
even a single character doesn't match, the test fails. This will 
probably surprise you a few times, as you learn exactly what Python 
does and doesn't guarantee about output. For example, when printing a 
dict, Python doesn't guarantee that the key-value pairs will be printed 
in any particular order, so a test like 


>>> foo()
{"Hermione": "hippogryph", "Harry": "broomstick"}

is vulnerable! One workaround is to do 


>>> foo() == {"Hermione": "hippogryph", "Harry": "broomstick"}
True

instead. Another is to do 


>>> d = foo().items()
>>> d.sort()
>>> d
[('Harry', 'broomstick'), ('Hermione', 'hippogryph')]