doctest fails to NORMALIZE_WHITESPACE ?

[David MacKay]

Hello, I'm a python-list newbie. I've got a question about doctest; perhaps 
a bug report.

I really like doctest, but sometimes doctest gives a failure when the output 
looks absolutely fine to me -- indeed, even after I have gone to considerable 
effort to make my documentation match the output perfectly.

http://www.aims.ac.za/~mackay/python/compression/huffman/Huffman3.py

The above file is an example.

It's self-contained, so you can plop it into emacs and hit C-cC-c to run the 
doctests. One of them fails. 
The piece of source code concerned is here: 

    >>> c = []; \
        c.append(node(0.5,1,'a')); \
        c.append(node(0.25,2,'b')); \
        c.append(node(0.125,3,'c')); \
        c.append(node(0.125,4,'d')); \
        iterate(c) ; reportcode(c)               # doctest: +NORMALIZE_WHITESPACE, +ELLIPSIS
    #Symbol	Count	Codeword
    a         (0.5)	1
    b         (0.25)	01
    c         (0.12)	000
    d         (0.12)	001
    """

And the output is: 

Failed example:
    c = [];         c.append(node(0.5,1,'a'));         c.append(node(0.25,2,'b'));         c.append(node(0.125,3,'c'));         c.append(node(0.125,4,'d'));         iterate(c) ; reportcode(c)               # doctest: +NORMALIZE_WHITESPACE, +ELLIPSIS
Expected:
    #Symbol     Count   Codeword
    a         (0.5)     1
    b         (0.25)    01
    c         (0.12)    000
    d         (0.12)    001
Got:
    <__main__.internalnode instance at 0xb7aee76c>
    #Symbol	Count	Codeword
    a	(0.5)	1
    b	(0.25)	01
    c	(0.12)	000
    d	(0.12)	001

===================================

I have tried numerous tweaks, and am at a loss. I am wondering whether there
is some big in doctest involving the "#" character in the output.
Or maybe I made some silly mistake.

Any advice appreciated!

Many thanks again to the authors of doctest, it gives a great feeling 
to write code in the way that doctest encourages. :-)

David

--
David J.C. MacKay     mackay at aims.ac.za     787 9336
                      http://www.aims.ac.za/~mackay/