Exploring Python's __subclasshook__ and Pattern Matching Edge Cases
By
agluszak
Crisp on the outside, thoughtful on the inside. A keeper.
Summary
The article explores creative and potentially problematic uses of Python's __subclasshook__ feature, particularly how it can be combined with Python 3.10's pattern matching to create non-standard type behaviors. The author demonstrates how to make objects match patterns they shouldn't technically match, essentially "tricking" Python's pattern matching system. This is presented as a fun but potentially dangerous exploration of Python's type system capabilities.
Key quotes
· 4 pulledAbstract Base Classes with __subclasshook__ can define what counts as a subclass of the ABC, even if the target doesn't know about the ABC
You can do some weird stuff with this
Then Python 3.10 added pattern matching
Let's make the CPython team regret adding pattern matching to Python!
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