How do I test dictionary-equality with Python's doctest-package?

Question

I'm writing a doctest for a function that outputs a dictionary. The doctest looks like

>>> my_function() {'this': 'is', 'a': 'dictionary'} 

When I run it, it fails with

Expected:     {'this': 'is', 'a': 'dictionary'} Got:     {'a': 'dictionary', 'this': 'is'} 

My best guess as to the cause of this failure is that doctest isn't checking dictionary equality, but __repr__ equality. This post indicates that there's some way to trick doctest into checking dictionary equality. How can I do this?

Answer 1

Another good way is to use pprint (in the standard library).

>>> import pprint >>> pprint.pprint({"second": 1, "first": 0}) {'first': 0, 'second': 1} 

According to its source code, it's sorting dicts for you:

http://hg.python.org/cpython/file/2.7/Lib/pprint.py#l158

items = _sorted(object.items())