doctests compatibility for python 2 & python 3

[Chris Angelico]

On Fri, Jan 17, 2014 at 10:16 PM, Robin Becker <robin at reportlab.com> wrote:
> Aside from changing the tests so they look like
>     """
>     >>> func(u'aaa')==u'aaa'
>     True
>     """

Do your test strings contain any non-ASCII characters? If not, you
might be able to do this:

def func(a):
    """
    >>> str(func(u'aaa'))
    'aaa'
    """
    return a

which should work in both. In Py3, the str() call will do nothing, and
it'll compare correctly; in Py2, it'll convert it into a byte string,
which will repr() without the 'u'.

I don't think it's possible to monkey-patch unicode.__repr__ to not
put the u'' prefix on, but if there is a way, that'd possibly be more
convenient.

ChrisA