Add support for dataclass fields init

docs/concepts/fields.md

@@ -459,6 +459,7 @@ print(foo)
 
 There are fields that can be used to constrain dataclasses:
 
+* `init`: Whether the field should be included in the `__init__` of the dataclass.
 * `init_var`: Whether the field should be seen as an [init-only field] in the dataclass.
 * `kw_only`: Whether the field should be a keyword-only argument in the constructor of the dataclass.
 

pydantic/_internal/_generate_schema.py

@@ -941,6 +941,7 @@ def _generate_dc_field_schema(
         return core_schema.dataclass_field(
             name,
             common_field['schema'],
+            init=field_info.init,
             init_only=field_info.init_var or None,
             kw_only=None if field_info.kw_only else False,
             serialization_exclude=common_field['serialization_exclude'],

pydantic/fields.py

@@ -64,6 +64,7 @@ class _FromFieldInfoInputs(typing_extensions.TypedDict, total=False):
     frozen: bool | None
     validate_default: bool | None
     repr: bool
+    init: bool | None
     init_var: bool | None
     kw_only: bool | None
 
@@ -101,7 +102,8 @@ class FieldInfo(_repr.Representation):
         frozen: Whether the field is frozen.
         validate_default: Whether to validate the default value of the field.
         repr: Whether to include the field in representation of the model.
-        init_var: Whether the field should be included in the constructor of the dataclass.
+        init: Whether the field should be included in the constructor of the dataclass.
+        init_var: Whether the field should _only_ be included in the constructor of the dataclass, and not stored.
         kw_only: Whether the field should be a keyword-only argument in the constructor of the dataclass.
         metadata: List of metadata constraints.
     """
@@ -122,6 +124,7 @@ class FieldInfo(_repr.Representation):
     frozen: bool | None
     validate_default: bool | None
     repr: bool
+    init: bool | None
     init_var: bool | None
     kw_only: bool | None
     metadata: list[Any]
@@ -143,6 +146,7 @@ class FieldInfo(_repr.Representation):
         'frozen',
         'validate_default',
         'repr',
+        'init',
         'init_var',
         'kw_only',
         'metadata',
@@ -203,6 +207,7 @@ def __init__(self, **kwargs: Unpack[_FieldInfoInputs]) -> None:
         self.validate_default = kwargs.pop('validate_default', None)
         self.frozen = kwargs.pop('frozen', None)
         # currently only used on dataclasses
+        self.init = kwargs.pop('init', None)
         self.init_var = kwargs.pop('init_var', None)
         self.kw_only = kwargs.pop('kw_only', None)
 
@@ -360,6 +365,7 @@ class MyModel(pydantic.BaseModel):
             )
             pydantic_field.frozen = final or pydantic_field.frozen
             pydantic_field.init_var = init_var
+            pydantic_field.init = getattr(default, 'init', None)
             pydantic_field.kw_only = getattr(default, 'kw_only', None)
             return pydantic_field
         else:
@@ -596,6 +602,7 @@ class _EmptyKwargs(typing_extensions.TypedDict):
     frozen=None,
     validate_default=None,
     repr=True,
+    init=None,
     init_var=None,
     kw_only=None,
     pattern=None,
@@ -630,6 +637,7 @@ def Field(  # noqa: C901
     frozen: bool | None = _Unset,
     validate_default: bool | None = _Unset,
     repr: bool = _Unset,
+    init: bool | None = _Unset,
     init_var: bool | None = _Unset,
     kw_only: bool | None = _Unset,
     pattern: str | None = _Unset,
@@ -675,7 +683,9 @@ def Field(  # noqa: C901
         validate_default: If `True`, apply validation to the default value every time you create an instance.
             Otherwise, for performance reasons, the default value of the field is trusted and not validated.
         repr: A boolean indicating whether to include the field in the `__repr__` output.
-        init_var: Whether the field should be included in the constructor of the dataclass.
+        init: Whether the field should be included in the constructor of the dataclass.
+            (Only applies to dataclasses.)
+        init_var: Whether the field should _only_ be included in the constructor of the dataclass.
             (Only applies to dataclasses.)
         kw_only: Whether the field should be a keyword-only argument in the constructor of the dataclass.
             (Only applies to dataclasses.)
@@ -784,6 +794,7 @@ def Field(  # noqa: C901
         pattern=pattern,
         validate_default=validate_default,
         repr=repr,
+        init=init,
         init_var=init_var,
         kw_only=kw_only,
         strict=strict,