GH-100242: bring functools.py partial implementation more in line with C code #100244
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in partial.__new__, before checking for the existence of the attribute 'func', first check whether the argument is an instance of partial.
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| Name | Link |
|---|---|
| 97b9966 | |
| https://app.netlify.com/sites/python-cpython-preview/deploys/6399fa45bbd72a0008fec2cf |
Lib/functools.py
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| @@ -284,7 +284,7 @@ def __new__(cls, func, /, *args, **keywords): | |||
| if not callable(func): | |||
| raise TypeError("the first argument must be callable") | |||
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| if hasattr(func, "func"): | |||
| if isinstance(func, partial) and hasattr(func, "func"): | |||
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Will an instance of partial ever not have a func attribute? Could this be simplified to just an isinstance() check?
| if isinstance(func, partial) and hasattr(func, "func"): | |
| if isinstance(func, partial): |
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yes, that works for me too. (you can certainly remove the func attribute from a pure python partial instance, but the resulting object is not very useful)
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if we do that, maybe it's also a good idea to just use an isinstance check in the C implementation as well? then the two approaches are straightforwardly identical.
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you can certainly remove the func attribute from a pure python partial instance, but the resulting object is not very useful
Yeah, if people are deleting the func attribute from partial objects, I have a lot of questions about their broader approach to programming in general :)
maybe it's also a good idea to just use an isinstance check in the C implementation as well?
I'm not qualified to comment on the C implementation, so I'll defer to you and @rhettinger on that question :)
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Yeah, if people are deleting the func attribute from partial objects, I have a lot of questions about their broader approach to programming in general :)
this argument convinced me ;-). I just went with the isinstance check in both places.
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As a first approximation this looks good. In the next couple of days, I can devote some time to give it more thought. |
in
partial.__new__, before checking for the existence of the attribute 'func', first check whether the argument is an instance of partial.