starting on alias API unification

Author: sydney-runkle

python/pydantic_core/core_schema.py

@@ -54,8 +54,6 @@ class CoreConfig(TypedDict, total=False):
             `field_names` to construct error `loc`s. Default is `True`.
         revalidate_instances: Whether instances of models and dataclasses should re-validate. Default is 'never'.
         validate_default: Whether to validate default values during validation. Default is `False`.
-        populate_by_name: Whether an aliased field may be populated by its name as given by the model attribute,
-            as well as the alias. (Replaces 'allow_population_by_field_name' in Pydantic v1.) Default is `False`.
         str_max_length: The maximum length for string fields.
         str_min_length: The minimum length for string fields.
         str_strip_whitespace: Whether to strip whitespace from string fields.
@@ -74,6 +72,9 @@ class CoreConfig(TypedDict, total=False):
         regex_engine: The regex engine to use for regex pattern validation. Default is 'rust-regex'. See `StringSchema`.
         cache_strings: Whether to cache strings. Default is `True`, `True` or `'all'` is required to cache strings
             during general validation since validators don't know if they're in a key or a value.
+        validate_by_alias: Whether to validate by alias. Default is `True`.
+        validate_by_name: Whether to validate by attribute name. Default is `False`. Replacement for `populate_by_name`.
+        serialize_by_alias: Whether to serialize by alias. Default is `False`, expected to change to `True` in V3.
     """
 
     title: str
@@ -91,7 +92,6 @@ class CoreConfig(TypedDict, total=False):
     # whether to validate default values during validation, default False
     validate_default: bool
     # used on typed-dicts and arguments
-    populate_by_name: bool  # replaces `allow_population_by_field_name` in pydantic v1
     # fields related to string fields only
     str_max_length: int
     str_min_length: int
@@ -111,6 +111,9 @@ class CoreConfig(TypedDict, total=False):
     coerce_numbers_to_str: bool  # default: False
     regex_engine: Literal['rust-regex', 'python-re']  # default: 'rust-regex'
     cache_strings: Union[bool, Literal['all', 'keys', 'none']]  # default: 'True'
+    validate_by_alias: bool  # default: True
+    validate_by_name: bool  # default: False
+    serialize_by_alias: bool  # default: False
 
 
 IncExCall: TypeAlias = 'set[int | str] | dict[int | str, IncExCall] | None'
@@ -2888,7 +2891,6 @@ class TypedDictSchema(TypedDict, total=False):
     # all these values can be set via config, equivalent fields have `typed_dict_` prefix
     extra_behavior: ExtraBehavior
     total: bool  # default: True
-    populate_by_name: bool  # replaces `allow_population_by_field_name` in pydantic v1
     ref: str
     metadata: dict[str, Any]
     serialization: SerSchema
@@ -2904,7 +2906,6 @@ def typed_dict_schema(
     extras_schema: CoreSchema | None = None,
     extra_behavior: ExtraBehavior | None = None,
     total: bool | None = None,
-    populate_by_name: bool | None = None,
     ref: str | None = None,
     metadata: dict[str, Any] | None = None,
     serialization: SerSchema | None = None,
@@ -2938,7 +2939,6 @@ class MyTypedDict(TypedDict):
         metadata: Any other information you want to include with the schema, not used by pydantic-core
         extra_behavior: The extra behavior to use for the typed dict
         total: Whether the typed dict is total, otherwise uses `typed_dict_total` from config
-        populate_by_name: Whether the typed dict should populate by name
         serialization: Custom serialization schema
     """
     return _dict_not_none(
@@ -2950,7 +2950,6 @@ class MyTypedDict(TypedDict):
         extras_schema=extras_schema,
         extra_behavior=extra_behavior,
         total=total,
-        populate_by_name=populate_by_name,
         ref=ref,
         metadata=metadata,
         serialization=serialization,
@@ -3012,9 +3011,7 @@ class ModelFieldsSchema(TypedDict, total=False):
     computed_fields: list[ComputedField]
     strict: bool
     extras_schema: CoreSchema
-    # all these values can be set via config, equivalent fields have `typed_dict_` prefix
     extra_behavior: ExtraBehavior
-    populate_by_name: bool  # replaces `allow_population_by_field_name` in pydantic v1
     from_attributes: bool
     ref: str
     metadata: dict[str, Any]
@@ -3029,7 +3026,6 @@ def model_fields_schema(
     strict: bool | None = None,
     extras_schema: CoreSchema | None = None,
     extra_behavior: ExtraBehavior | None = None,
-    populate_by_name: bool | None = None,
     from_attributes: bool | None = None,
     ref: str | None = None,
     metadata: dict[str, Any] | None = None,
@@ -3058,7 +3054,6 @@ def model_fields_schema(
         ref: optional unique identifier of the schema, used to reference the schema in other places
         metadata: Any other information you want to include with the schema, not used by pydantic-core
         extra_behavior: The extra behavior to use for the typed dict
-        populate_by_name: Whether the typed dict should populate by name
         from_attributes: Whether the typed dict should be populated from attributes
         serialization: Custom serialization schema
     """
@@ -3070,7 +3065,6 @@ def model_fields_schema(
         strict=strict,
         extras_schema=extras_schema,
         extra_behavior=extra_behavior,
-        populate_by_name=populate_by_name,
         from_attributes=from_attributes,
         ref=ref,
         metadata=metadata,
@@ -3254,7 +3248,6 @@ class DataclassArgsSchema(TypedDict, total=False):
     dataclass_name: Required[str]
     fields: Required[list[DataclassField]]
     computed_fields: list[ComputedField]
-    populate_by_name: bool  # default: False
     collect_init_only: bool  # default: False
     ref: str
     metadata: dict[str, Any]
@@ -3267,7 +3260,6 @@ def dataclass_args_schema(
     fields: list[DataclassField],
     *,
     computed_fields: list[ComputedField] | None = None,
-    populate_by_name: bool | None = None,
     collect_init_only: bool | None = None,
     ref: str | None = None,
     metadata: dict[str, Any] | None = None,
@@ -3295,7 +3287,6 @@ def dataclass_args_schema(
         dataclass_name: The name of the dataclass being validated
         fields: The fields to use for the dataclass
         computed_fields: Computed fields to use when serializing the dataclass
-        populate_by_name: Whether to populate by name
         collect_init_only: Whether to collect init only fields into a dict to pass to `__post_init__`
         ref: optional unique identifier of the schema, used to reference the schema in other places
         metadata: Any other information you want to include with the schema, not used by pydantic-core
@@ -3307,7 +3298,6 @@ def dataclass_args_schema(
         dataclass_name=dataclass_name,
         fields=fields,
         computed_fields=computed_fields,
-        populate_by_name=populate_by_name,
         collect_init_only=collect_init_only,
         ref=ref,
         metadata=metadata,
@@ -3436,7 +3426,8 @@ def arguments_parameter(
 class ArgumentsSchema(TypedDict, total=False):
     type: Required[Literal['arguments']]
     arguments_schema: Required[list[ArgumentsParameter]]
-    populate_by_name: bool
+    validate_by_name: bool
+    validate_by_alias: bool
     var_args_schema: CoreSchema
     var_kwargs_mode: VarKwargsMode
     var_kwargs_schema: CoreSchema
@@ -3448,7 +3439,8 @@ class ArgumentsSchema(TypedDict, total=False):
 def arguments_schema(
     arguments: list[ArgumentsParameter],
     *,
-    populate_by_name: bool | None = None,
+    validate_by_name: bool | None = None,
+    validate_by_alias: bool | None = None,
     var_args_schema: CoreSchema | None = None,
     var_kwargs_mode: VarKwargsMode | None = None,
     var_kwargs_schema: CoreSchema | None = None,
@@ -3475,7 +3467,8 @@ def arguments_schema(
 
     Args:
         arguments: The arguments to use for the arguments schema
-        populate_by_name: Whether to populate by name
+        validate_by_name: Whether to populate by argument names, defaults to False.
+        validate_by_alias: Whether to populate by argument aliases, defaults to True.
         var_args_schema: The variable args schema to use for the arguments schema
         var_kwargs_mode: The validation mode to use for variadic keyword arguments. If `'uniform'`, every value of the
             keyword arguments will be validated against the `var_kwargs_schema` schema. If `'unpacked-typed-dict'`,
@@ -3488,7 +3481,8 @@ def arguments_schema(
     return _dict_not_none(
         type='arguments',
         arguments_schema=arguments,
-        populate_by_name=populate_by_name,
+        validate_by_name=validate_by_name,
+        validate_by_alias=validate_by_alias,
         var_args_schema=var_args_schema,
         var_kwargs_mode=var_kwargs_mode,
         var_kwargs_schema=var_kwargs_schema,

src/validators/arguments.rs

@@ -8,7 +8,7 @@ use ahash::AHashSet;
 use pyo3::IntoPyObjectExt;
 
 use crate::build_tools::py_schema_err;
-use crate::build_tools::{schema_or_config_same, ExtraBehavior};
+use crate::build_tools::ExtraBehavior;
 use crate::errors::{ErrorTypeDefaults, ValError, ValLineError, ValResult};
 use crate::input::{Arguments, BorrowInput, Input, KeywordArgs, PositionalArgs, ValidationMatch};
 use crate::lookup_key::LookupKey;
@@ -68,7 +68,7 @@ impl BuildValidator for ArgumentsValidator {
     ) -> PyResult<CombinedValidator> {
         let py = schema.py();
 
-        let populate_by_name = schema_or_config_same(schema, config, intern!(py, "populate_by_name"))?.unwrap_or(false);
+        let validate_by_name = config.get_as(intern!(py, "validate_by_name"))?.unwrap_or(false);
 
         let arguments_schema: Bound<'_, PyList> = schema.get_as_req(intern!(py, "arguments_schema"))?;
         let mut parameters: Vec<Parameter> = Vec::with_capacity(arguments_schema.len());
@@ -102,7 +102,7 @@ impl BuildValidator for ArgumentsValidator {
             if mode == "keyword_only" || mode == "positional_or_keyword" {
                 kw_lookup_key = match arg.get_item(intern!(py, "alias"))? {
                     Some(alias) => {
-                        let alt_alias = if populate_by_name { Some(name.as_str()) } else { None };
+                        let alt_alias = if validate_by_name { Some(name.as_str()) } else { None };
                         Some(LookupKey::from_py(py, &alias, alt_alias)?)
                     }
                     None => Some(LookupKey::from_string(py, &name)),

src/validators/dataclass.rs

@@ -54,7 +54,7 @@ impl BuildValidator for DataclassArgsValidator {
     ) -> PyResult<CombinedValidator> {
         let py = schema.py();
 
-        let populate_by_name = schema_or_config_same(schema, config, intern!(py, "populate_by_name"))?.unwrap_or(false);
+        let validate_by_name = config.get_as(intern!(py, "validate_by_name"))?.unwrap_or(false);
 
         let extra_behavior = ExtraBehavior::from_schema_or_config(py, schema, config, ExtraBehavior::Ignore)?;
 
@@ -77,7 +77,7 @@ impl BuildValidator for DataclassArgsValidator {
 
             let lookup_key = match field.get_item(intern!(py, "validation_alias"))? {
                 Some(alias) => {
-                    let alt_alias = if populate_by_name { Some(name.as_str()) } else { None };
+                    let alt_alias = if validate_by_name { Some(name.as_str()) } else { None };
                     LookupKey::from_py(py, &alias, alt_alias)?
                 }
                 None => LookupKey::from_string(py, &name),

src/validators/model_fields.rs

@@ -51,7 +51,7 @@ impl BuildValidator for ModelFieldsValidator {
         let strict = is_strict(schema, config)?;
 
         let from_attributes = schema_or_config_same(schema, config, intern!(py, "from_attributes"))?.unwrap_or(false);
-        let populate_by_name = schema_or_config_same(schema, config, intern!(py, "populate_by_name"))?.unwrap_or(false);
+        let validate_by_name = config.get_as(intern!(py, "validate_by_name"))?.unwrap_or(false);
 
         let extra_behavior = ExtraBehavior::from_schema_or_config(py, schema, config, ExtraBehavior::Ignore)?;
 
@@ -81,7 +81,7 @@ impl BuildValidator for ModelFieldsValidator {
 
             let lookup_key = match field_info.get_item(intern!(py, "validation_alias"))? {
                 Some(alias) => {
-                    let alt_alias = if populate_by_name { Some(field_name) } else { None };
+                    let alt_alias = if validate_by_name { Some(field_name) } else { None };
                     LookupKey::from_py(py, &alias, alt_alias)?
                 }
                 None => LookupKey::from_string(py, field_name),

src/validators/typed_dict.rs

@@ -3,7 +3,7 @@ use pyo3::prelude::*;
 use pyo3::types::{PyDict, PyString};
 
 use crate::build_tools::py_schema_err;
-use crate::build_tools::{is_strict, schema_or_config, schema_or_config_same, ExtraBehavior};
+use crate::build_tools::{is_strict, schema_or_config, ExtraBehavior};
 use crate::errors::LocItem;
 use crate::errors::{ErrorTypeDefaults, ValError, ValLineError, ValResult};
 use crate::input::BorrowInput;
@@ -55,7 +55,7 @@ impl BuildValidator for TypedDictValidator {
 
         let total =
             schema_or_config(schema, config, intern!(py, "total"), intern!(py, "typed_dict_total"))?.unwrap_or(true);
-        let populate_by_name = schema_or_config_same(schema, config, intern!(py, "populate_by_name"))?.unwrap_or(false);
+        let validate_by_name = config.get_as(intern!(py, "validate_by_name"))?.unwrap_or(false);
 
         let extra_behavior = ExtraBehavior::from_schema_or_config(py, schema, config, ExtraBehavior::Ignore)?;
 
@@ -110,7 +110,7 @@ impl BuildValidator for TypedDictValidator {
 
             let lookup_key = match field_info.get_item(intern!(py, "validation_alias"))? {
                 Some(alias) => {
-                    let alt_alias = if populate_by_name { Some(field_name) } else { None };
+                    let alt_alias = if validate_by_name { Some(field_name) } else { None };
                     LookupKey::from_py(py, &alias, alt_alias)?
                 }
                 None => LookupKey::from_string(py, field_name),

tests/validators/test_arguments.py

@@ -883,14 +883,14 @@ def test_alias(py_and_json: PyAndJson, input_value, expected):
     ],
     ids=repr,
 )
-def test_alias_populate_by_name(py_and_json: PyAndJson, input_value, expected):
+def test_alias_validate_by_name(py_and_json: PyAndJson, input_value, expected):
     v = py_and_json(
         {
             'type': 'arguments',
             'arguments_schema': [
                 {'name': 'a', 'mode': 'positional_or_keyword', 'schema': {'type': 'int'}, 'alias': 'Foo'}
             ],
-            'populate_by_name': True,
+            'validate_by_name': True,
         }
     )
     if isinstance(expected, Err):

tests/validators/test_model_fields.py

@@ -506,9 +506,9 @@ def test_alias_allow_pop(py_and_json: PyAndJson):
     v = py_and_json(
         {
             'type': 'model-fields',
-            'populate_by_name': True,
             'fields': {'field_a': {'validation_alias': 'FieldA', 'type': 'model-field', 'schema': {'type': 'int'}}},
-        }
+        },
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_test({'FieldA': '123'}) == ({'field_a': 123}, None, {'field_a'})
     assert v.validate_test({'field_a': '123'}) == ({'field_a': 123}, None, {'field_a'})
@@ -697,8 +697,8 @@ def test_paths_allow_by_name(py_and_json: PyAndJson, input_value):
                     'schema': {'type': 'int'},
                 }
             },
-            'populate_by_name': True,
-        }
+        },
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_test(input_value) == ({'field_a': 42}, None, {'field_a'})
 
@@ -985,8 +985,8 @@ def test_from_attributes_by_name():
         core_schema.model_fields_schema(
             fields={'a': core_schema.model_field(schema=core_schema.int_schema(), validation_alias='a_alias')},
             from_attributes=True,
-            populate_by_name=True,
-        )
+        ),
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_python(Cls(a_alias=1)) == ({'a': 1}, None, {'a'})
     assert v.validate_python(Cls(a=1)) == ({'a': 1}, None, {'a'})
@@ -1383,9 +1383,9 @@ def test_alias_extra_by_name(py_and_json: PyAndJson):
             'type': 'model-fields',
             'extra_behavior': 'allow',
             'from_attributes': True,
-            'populate_by_name': True,
             'fields': {'field_a': {'validation_alias': 'FieldA', 'type': 'model-field', 'schema': {'type': 'int'}}},
-        }
+        },
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_test({'FieldA': 1}) == ({'field_a': 1}, {}, {'field_a'})
     assert v.validate_test({'field_a': 1}) == ({'field_a': 1}, {}, {'field_a'})

tests/validators/test_typed_dict.py

@@ -393,11 +393,11 @@ def test_alias_allow_pop(py_and_json: PyAndJson):
     v = py_and_json(
         {
             'type': 'typed-dict',
-            'populate_by_name': True,
             'fields': {
                 'field_a': {'validation_alias': 'FieldA', 'type': 'typed-dict-field', 'schema': {'type': 'int'}}
             },
-        }
+        },
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_test({'FieldA': '123'}) == {'field_a': 123}
     assert v.validate_test({'field_a': '123'}) == {'field_a': 123}
@@ -590,8 +590,8 @@ def test_paths_allow_by_name(py_and_json: PyAndJson, input_value):
                     'schema': {'type': 'int'},
                 }
             },
-            'populate_by_name': True,
-        }
+        },
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_test(input_value) == {'field_a': 42}
 
@@ -795,11 +795,11 @@ def test_alias_extra_by_name(py_and_json: PyAndJson):
         {
             'type': 'typed-dict',
             'extra_behavior': 'allow',
-            'populate_by_name': True,
             'fields': {
                 'field_a': {'validation_alias': 'FieldA', 'type': 'typed-dict-field', 'schema': {'type': 'int'}}
             },
-        }
+        },
+        config=CoreConfig(validate_by_name=True),
     )
     assert v.validate_test({'FieldA': 1}) == {'field_a': 1}
     assert v.validate_test({'field_a': 1}) == {'field_a': 1}