Message313096
I'm always writting these wrapper classes where I want to selectively want to expose the interface of some of the methods of certain attributes to co the containing object. This can mean I spend a lot of time implementing wrapper methods. That's no good. I wrote a class decorator to make this easy, and I realized it's a perfect complement to the new dataclasses module, though it can also be used with normal classes. I figured I'd check if you're interested in that. The interface looks like this:
>>> from dataclasses import dataclass, acts_like
>>> @acts_like('weight', ['__add__'])
... @acts_like('still_fresh', ['__bool__'])
... @dataclass
... class Spam:
... weight: int
... still_fresh: bool
>>> s = Spam(42, False)
>>> s + 3
45
>>> if not s:
... print('the spam is bad')
the spam is bad
It's a handy way to build objects with composition, but still get some of the benefits of inheritance in a *selective* and *explicite* way.
Here's the code: https://github.com/ninjaaron/cpython/blob/acts_like/Lib/dataclasses.py#L978
May require some addtional twiddling to make it work with frozen dataclasses, but I don't think it should be a problem. |
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Date |
User |
Action |
Args |
2018-03-01 14:54:50 | ninjaaron | set | recipients:
+ ninjaaron, eric.smith |
2018-03-01 14:54:50 | ninjaaron | set | messageid: <1519916090.48.0.467229070634.issue32977@psf.upfronthosting.co.za> |
2018-03-01 14:54:50 | ninjaaron | link | issue32977 messages |
2018-03-01 14:54:50 | ninjaaron | create | |
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