Le 07/06/2014 09:25, R. David Murray a écrit :
On Fri, 06 Jun 2014 19:50:57 +0100, Chris Withers <ch...@simplistix.co.uk>
wrote:
I've been trying to add support for explicit comparison of namedtuples
into testfixtures and hit a problem which lead me to read the source and
be sad.
Rather than the mixin and class assembly in the function I expected to
find, I'm greeted by an exec of a string.
Curious as to what lead to that implementation approach? What does it
buy that couldn't have been obtained by a mixin providing the functionality?
In my case, that's somewhat irrelevant, I'm looking to store a comparer
in a registry that would get used for all namedtuples, but I have
nothing to key that off, there are no shared bases other than object and
tuple.
I guess I could duck-type it based on the _fields attribute but that
feels implicit and fragile.
What do you guys suggest?
I seem to remember a previous discussion that concluded that duck typing
based on _fields was the way to go. (It's a public API, despite the _,
due to name-tuple's attribute namespacing issues.)
There could be many third-party classes with a _fields member, so that
sounds rather fragile.
There doesn't seem to be any technical reason barring the addition of a
common base class for namedtuples.
Regards
Antoine.
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