https://github.com/python/cpython/commit/281fc338fdf57ef119e213bf1b2c772261c359c1
commit: 281fc338fdf57ef119e213bf1b2c772261c359c1
branch: main
author: Tapeline <m...@tapeline.dev>
committer: ericvsmith <ericvsm...@users.noreply.github.com>
date: 2025-04-13T12:47:44-04:00
summary:
gh-132111: Document dataclasses.InitVar (#132446)
files:
M Doc/library/dataclasses.rst
diff --git a/Doc/library/dataclasses.rst b/Doc/library/dataclasses.rst
index 0bc171da4eefc7..72612211b43d5e 100644
--- a/Doc/library/dataclasses.rst
+++ b/Doc/library/dataclasses.rst
@@ -344,6 +344,15 @@ Module contents
Other attributes may exist, but they are private and must not be
inspected or relied on.
+.. class:: InitVar
+
+ ``InitVar[T]`` type annotations describe variables that are :ref:`init-only
+ <dataclasses-init-only-variables>`. Fields annotated with :class:`!InitVar`
+ are considered pseudo-fields, and thus are neither returned by the
+ :func:`fields` function nor used in any way except adding them as
+ parameters to :meth:`~object.__init__` and an optional
+ :meth:`__post_init__`.
+
.. function:: fields(class_or_instance)
Returns a tuple of :class:`Field` objects that define the fields for this
@@ -600,8 +609,8 @@ Init-only variables
Another place where :func:`@dataclass <dataclass>` inspects a type annotation
is to
determine if a field is an init-only variable. It does this by seeing
-if the type of a field is of type ``dataclasses.InitVar``. If a field
-is an ``InitVar``, it is considered a pseudo-field called an init-only
+if the type of a field is of type :class:`InitVar`. If a field
+is an :class:`InitVar`, it is considered a pseudo-field called an init-only
field. As it is not a true field, it is not returned by the
module-level :func:`fields` function. Init-only fields are added as
parameters to the generated :meth:`~object.__init__` method, and are passed to
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