> But wait a minute, zip isn't just a "callable", it's a class, and adding more methods to it seems perfectly natural, just like lots of other built-in classes.
Zip is a class in CPython 3.8. it may or may not be in other implementations or versions. The API users are currently promised says nothing about it needing to be implemented as a class.
and it was a function in 2.7.
But though Python blurs the lines between various callables and functions, there is a general "sense" of how they are used. And for the most part, zip is not used like a class. WE "use" classes, usually, by creating instances, and then calling various methods on them, etc.
a zip instance on the other hand, returns an iterable, that does not provide any other methods or uses. I have to say, I have not idea why zip is a class rather than a function that returns a zip_iterator instance, but it is certainly an implementation detail.
So while yes, alternate constructors are a common pattern, I don't think they are a common pattern for classes like zip.
That being said, I still like it.
-CHB
Moreover, even if Python 3.9 decides to make zip() a function instead, that wouldn't prevent the alternate constructors being implemented.
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