Class Attribute

src/attr/_make.py:2429–2667

*Read-only* representation of an attribute. .. warning:: You should never instantiate this class yourself. The class has *all* arguments of `attr.ib` (except for ``factory`` which is only syntactic sugar for ``default=Factory(...)`` plus the following: - ``name`` (`st

class Attribute:
    class="st">"""
    *Read-only* representation of an attribute.

    .. warning::

       You should never instantiate this class yourself.

    The class has *all* arguments of `attr.ib` (except for ``factory`` which is
    only syntactic sugar for ``default=Factory(...)`` plus the following:

    - ``name`` (`str`): The name of the attribute.
    - ``alias`` (`str`): The __init__ parameter name of the attribute, after
      any explicit overrides and default private-attribute-name handling.
    - ``alias_is_default`` (`bool`): Whether the ``alias`` was automatically
      generated (``True``) or explicitly provided by the user (``False``).
    - ``inherited`` (`bool`): Whether or not that attribute has been inherited
      from a base class.
    - ``eq_key`` and ``order_key`` (`typing.Callable` or `None`): The
      callables that are used for comparing and ordering objects by this
      attribute, respectively. These are set by passing a callable to
      `attr.ib`&class="cm">#x27;s ``eq``, ``order``, or ``cmp`` arguments. See also
      :ref:`comparison customization <custom-comparison>`.

    Instances of this class are frequently used for introspection purposes
    like:

    - `fields` returns a tuple of them.
    - Validators get them passed as the first argument.
    - The :ref:`field transformer <transform-fields>` hook receives a list of
      them.
    - The ``alias`` property exposes the __init__ parameter name of the field,
      with any overrides and default private-attribute handling applied.


    .. versionadded:: 20.1.0 *inherited*
    .. versionadded:: 20.1.0 *on_setattr*
    .. versionchanged:: 20.2.0 *inherited* is not taken into account for
        equality checks and hashing anymore.
    .. versionadded:: 21.1.0 *eq_key* and *order_key*
    .. versionadded:: 22.2.0 *alias*
    .. versionadded:: 26.1.0 *alias_is_default*

    For the full version history of the fields, see `attr.ib`.
    class="st">"""

    class="cm"># These slots must NOT be reordered because we use them later for
    class="cm"># instantiation.
    __slots__ = (  class="cm"># noqa: RUF023
        class="st">"name",
        class="st">"default",
        class="st">"validator",
        class="st">"repr",
        class="st">"eq",
        class="st">"eq_key",
        class="st">"order",
        class="st">"order_key",
        class="st">"hash",