[Python-Dev] namedtuple implementation grumble

[Chris Withers]

Hi All,

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?

cheers,

Chris

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