Skip to content

gh-141510: Use frozendict for errno.errorcode#144906

Closed
vstinner wants to merge 1 commit intopython:mainfrom
vstinner:frozendict_errno
Closed

gh-141510: Use frozendict for errno.errorcode#144906
vstinner wants to merge 1 commit intopython:mainfrom
vstinner:frozendict_errno

Conversation

@vstinner
Copy link
Member

@vstinner vstinner commented Feb 17, 2026

@vstinner
Copy link
Member Author

cc @Yhg1s

add_errcode("ENOTCAPABLE", ENOTCAPABLE, "Capabilities insufficient");
#endif

PyObject *frozendict = PyFrozenDict_New(error_dict);
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think that we have to add new C API for frozendict with builder pattern.
This is inefficient for many people.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Well, frozendict is not widely used in C code yet. IMO it's too early to design an optimized API to build a new frozendict object. PyFrozenDict_New() should be good for now.

@Yhg1s
Copy link
Member

Yhg1s commented Feb 19, 2026

What's the rationale for using frozendict here? I don't think it's unreasonable at all for user/library code to want to add to errno.errorcode. We build the module contents from compile time constants, but we don't add any once the Python version is released. It's not at all unreasonable to want to add known errno values on older Python versions, or adding ones that weren't supported by the build environment.

@vstinner
Copy link
Member Author

Ah ok, in this case, I close my PR.

My rationale is that I wanted to disallow modifying existing error codes or adding new error codes. But you say that it's possible on purpose, so I prefer to close the PR.

@vstinner vstinner closed this Feb 19, 2026
@Yhg1s
Copy link
Member

Yhg1s commented Feb 19, 2026

Just to be clear: I'm not saying it's possible on purpose, just that I think it is a useful property even if it wasn't on purpose, and I do think we have to consider that people are using the mutability. That's the case for any existing, exposed dict: it may not make sense to mutate it, but maybe we just don't see the cases where it does make sense. We have to consider whether the change is worth the potential breakage, so I think we need a good, real-world reason to replace the dict with a frozendict, not just a theoretical, common-sense one.

@vstinner vstinner deleted the frozendict_errno branch February 19, 2026 15:55
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Projects

None yet

Development

Successfully merging this pull request may close these issues.

3 participants

Comments