doctest annoyance/puzzle

[Steven D'Aprano]

I'm writing a "literate programming" document, example.txt, which mixes
text and code in ReST format:

This is my excellent module for making spam. It has
one public function, ``make_spam``, which takes a
single argument for how much spam to make:

>>> from module import make_spam
>>> make_spam(3)
'spam spam spam'

If you ask for too little spam, you get a bonus:

>>> make_spam(-3)
'spam spam spam GLORIOUS SPAM!!!'

I run the doctests with:

python2.6 -m doctest examples.txt

and the first example passes, but the second fails with NameError:
make_spam not defined.

I have a work-around, I do an import at the start of *every* doctest
block, but that's ugly. More complex (realistic) examples sometimes need
setup code, which I'd like to survive from one block to the next:

>>> it = iter(make_spam(5).split())
>>> next(it)
'spam'

text goes here

>>> next(it)
'spam'

but of course that also fails. This surprises me, because doctests in
functions or classes can mix descriptive text between tests without this
problem.

Am I doing something wrong, or is doctest fundamentally broken when
executing tests in a text file?

--
Steven

[Stefan Schwarzer]

Hi Steven,

On 2010-09-05 17:30, Steven D'Aprano wrote:
> I run the doctests with:
>
> python2.6 -m doctest examples.txt
>
> and the first example passes, but the second fails with NameError:
> make_spam not defined.

I run my doctests by calling

doctest.testfile(filename)

for each file in a loop. This way, names and their
associated objects survice from one code block to the next.

I just read that the way you use doctest should behave the
same, according to the documentation. In case of a text file
I just tested, it does; all tests pass despite the text
snippets between the code blocks.

What do you get if you test your text file by explicitly
calling doctest.testfile?

Stefan

[Steven D'Aprano]

On Sun, 05 Sep 2010 18:41:15 +0200, Stefan Schwarzer wrote:

> Hi Steven,
>
> On 2010-09-05 17:30, Steven D'Aprano wrote:
>> I run the doctests with:
>>
>> python2.6 -m doctest examples.txt
>>
>> and the first example passes, but the second fails with NameError:
>> make_spam not defined.
>
> I run my doctests by calling
>
> doctest.testfile(filename)
>
> for each file in a loop. This way, names and their associated objects
> survice from one code block to the next.

That's fine if you're calling it from Python, but I want a way to run the
tests from the shell, and the advertised way to do that is by calling
doctest.py as a script. The module calls testfile, so it should work.

And now it's working for me. I have *no idea* what happened there... it
wasn't working for me before, and now it is.

Sorry for the noise :(

--
Steven