I am extremely excited to announce the release of attrs 21.1.0.
attrs is the direct ancestor of – and the inspiration for – dataclasses in the standard library and remains the more powerful option for creating regular classes without getting bogged down with writing identical boilerplate again and again: https://www.attrs.org/
Heartfelt thanks go to my generous GitHub sponsors, companies subscribing to attrs on Tidelift, and people who bought me a coffee on Ko-fi! Support like that makes me work on FOSS on a Saturday afternoon – especially when a release drags itself like this one! <3
While this release took a bit longer than I wished for, it comes with many exciting changes. The highlights alone are longer than a usual changelog:
The next-generation APIs (@attr.define, @attr.mutable, @attr.frozen, @attr.field) are deemed stable now. The old ones aren't going anywhere, but I encourage you to check the new ones out – they're much nicer!
pyright and pylance support: Eric Traut of Microsoft was kind enough to involve me in their work on the dataclass_transforms spec.
As a result, Microsoft's type checker pyright will work with this attrs release, and so will their Python language server pylance which should be exciting to VS Code users.
Currently it only supports a subset of attrs's features, but it's the most important ones and more will most likely follow. Some of the limitations are documented in our documentation on type annotations.
Customization of field comparison. This is something especially NumPy users have been asking for for a long time: you can now fully customize how a field is compared. We also ship a helper to avoid boilerplate code. So if you'd like to have an object with a NumPy array that compares correctly, this is the way:
import attr
import numpy
@attr.define
class C:
an_array = attr.field(eq=attr.cmp_using(eq=numpy.array_equal))
To make it more ergonomic, I've decided to un-deprecate the cmp argument again, so you can customize eq and order in one go. Sorry about the trouble! The cmpattribute remains deprecated.
New powerful __init__ helpers:
If attrs deduces you don't want it to write a __init__ for you, it will create an __attrs_init__ instead that you can call from your custom __init__.
If attrs finds a __attrs_pre_init__, it will call it without any arguments before doing any initializations. This is really only useful if you want to run super().__init__(), but that's a use-case people have asked for for years!
In preparation for the (rescinded) plan to make from __future__ import annotations the default in Python 3.10, attr.resolve_types() can now also be used to resolve types inside of field_transformers.
A Look Ahead
For the next release we've got even bigger plans! By stabilizing the next-generation APIs we can finally go the last step, I've been talking for years (yeah, sorry): import attrs.
attrs's playful APIs (@attr.s, @attr.ib) lost a bit of their charm as the scope of the package grew – especially after the introduction of type annotations.
While the old APIs aren't going anywhere, in the next feature release there will be additionally an attrs package that you can use as an alternative to attr. No more attr.Factory!
The new package gives us the opportunity to rethink the defaults of some functions. So if you have any pet peeves, please air them on #487.
The long-awaited, much-talked-about, little-delivered import attrs is finally upon us!
Since the NG APIs have now been proclaimed stable, the next release of attrs will allow you to actually import attrs. We're taking this opportunity to replace some defaults in our APIs that made sense in 2015, but don't in 2021.
So please, if you have any pet peeves about defaults in attrs's APIs, now is the time to air your grievances in #487! We're not gonna get such a chance for a second time, without breaking our backward-compatibility guarantees, or long deprecation cycles. Therefore, speak now or forever hold you peace! #487
The cmp argument to attr.s() and attr.ib() has been undeprecated It will continue to be supported as syntactic sugar to set eq and order in one go.
I'm terribly sorry for the hassle around this argument! The reason we're bringing it back is it's usefulness regarding customization of equality/ordering.
The cmp attribute and argument on attr.Attribute remains deprecated and will be removed later this year. #773
Changes
It's now possible to customize the behavior of eq and order by passing in a callable. #435, #627
Added provisional support for static typing in pyright via the dataclass_transforms specification. Both the pyright specification and attrs implementation may change in future versions of both projects.
Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.
If all status checks pass Dependabot will automatically merge this pull request.
Dependabot commands and options
You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
- `@dependabot use these labels` will set the current labels as the default for future PRs for this repo and language
- `@dependabot use these reviewers` will set the current reviewers as the default for future PRs for this repo and language
- `@dependabot use these assignees` will set the current assignees as the default for future PRs for this repo and language
- `@dependabot use this milestone` will set the current milestone as the default for future PRs for this repo and language
- `@dependabot badge me` will comment on this PR with code to add a "Dependabot enabled" badge to your readme
Additionally, you can set the following in your Dependabot [dashboard](https://app.dependabot.com):
- Update frequency (including time of day and day of week)
- Pull request limits (per update run and/or open at any time)
- Automerge options (never/patch/minor, and dev/runtime dependencies)
- Out-of-range updates (receive only lockfile updates, if desired)
- Security updates (receive only security updates, if desired)
Bumps attrs from 20.3.0 to 21.1.0.
Release notes
Sourced from attrs's releases.
... (truncated)
Changelog
Sourced from attrs's changelog.
... (truncated)
Commits
b22195e
Prepare 21.1.0c5ae43f
Pin towncrier503164f
Fix changelog template for towncrier 21.3.0fbed032
Revert last change, the string is consistent w/ total_ordering2f395f1
Make docstring consistent with the restf41db43
Unpin pyright & minor docs polish16f7a0d
Make #796 newsfragment more timelesseb2df7f
Add announcement aboutimport attrs
c6f6bb3
Revert "Pin 3.10 to last alpha (#802)"7e372c5
Implement pyright support via dataclass_transforms (#796)Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting
@dependabot rebase
.If all status checks pass Dependabot will automatically merge this pull request.
Dependabot commands and options
You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself) - `@dependabot use these labels` will set the current labels as the default for future PRs for this repo and language - `@dependabot use these reviewers` will set the current reviewers as the default for future PRs for this repo and language - `@dependabot use these assignees` will set the current assignees as the default for future PRs for this repo and language - `@dependabot use this milestone` will set the current milestone as the default for future PRs for this repo and language - `@dependabot badge me` will comment on this PR with code to add a "Dependabot enabled" badge to your readme Additionally, you can set the following in your Dependabot [dashboard](https://app.dependabot.com): - Update frequency (including time of day and day of week) - Pull request limits (per update run and/or open at any time) - Automerge options (never/patch/minor, and dev/runtime dependencies) - Out-of-range updates (receive only lockfile updates, if desired) - Security updates (receive only security updates, if desired)