reame get_validators > __get_validators__ (#338)

* reame get_validators > __get_validators__

* update docs

HISTORY.rst

@@ -16,6 +16,7 @@ v0.17.0 (unreleased)
   (**breaking change**: this supersedes the ``validate_assignment`` argument with ``config``)
 * support for nested dataclasses, #334 by @samuelcolvin
 * better errors when getting an ``ImportError`` with ``PyObject``, #309 by @samuelcolvin
+* rename ``get_validators`` to ``__get_validators__``, deprecation warning on use of old name, #338 by @samuelcolvin
 
 v0.16.1 (2018-12-10)
 ....................

docs/examples/custom_data_types.py

@@ -3,7 +3,7 @@ from pydantic import BaseModel, ValidationError
 
 class StrictStr(str):
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield cls.validate
 
     @classmethod

docs/index.rst

@@ -391,8 +391,13 @@ against defined Json structure if it's provided.
 Custom Data Types
 .................
 
-You can also define your own data types. Class method ``get_validators`` will be called to get validators to parse and
-validate the input data.
+You can also define your own data types. The class method ``__get_validators__`` will be called
+to get validators to parse and validate the input data.
+
+.. note::
+
+   The name of ``__get_validators__`` was changed from ``get_validators`` in ``v0.17``,
+   the old name is currently still supported but deprecated and will be removed in future.
 
 .. literalinclude:: examples/custom_data_types.py
 

pydantic/fields.py

@@ -1,4 +1,5 @@
 import inspect
+import warnings
 from enum import IntEnum
 from typing import Any, Callable, Dict, List, Mapping, NamedTuple, Pattern, Set, Tuple, Type, Union
 
@@ -201,8 +202,13 @@ class Field:
     def _populate_validators(self):
         class_validators_ = self.class_validators.values()
         if not self.sub_fields:
-            get_validators = getattr(self.type_, 'get_validators', None)
-            get_validators = get_validators or getattr(self.type_, '__get_validators__', None)
+            get_validators = getattr(self.type_, '__get_validators__', None)
+            if not get_validators:
+                get_validators = getattr(self.type_, 'get_validators', None)
+                if get_validators:
+                    warnings.warn(
+                        f'get_validators has been replaced by __get_validators__ (on {self.name})', DeprecationWarning
+                    )
             v_funcs = (
                 *tuple(v.func for v in class_validators_ if not v.whole and v.pre),
                 *(

pydantic/main.py

@@ -345,7 +345,7 @@ class BaseModel(metaclass=MetaModel):
         return json.dumps(cls.schema(by_alias=by_alias), default=pydantic_encoder, **dumps_kwargs)
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield dict_validator
         yield cls.validate
 

pydantic/types.py

@@ -67,7 +67,7 @@ NoneStrBytes = Optional[StrBytes]
 
 class StrictStr(str):
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield cls.validate
 
     @classmethod
@@ -85,7 +85,7 @@ class ConstrainedStr(str):
     regex: Optional[Pattern] = None
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield not_none_validator
         yield str_validator
         yield anystr_strip_whitespace
@@ -118,7 +118,7 @@ def constr(*, strip_whitespace=False, min_length=None, max_length=None, curtail_
 
 class EmailStr(str):
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         # included here and below so the error happens straight away
         if email_validator is None:
             raise ImportError('email-validator is not installed, run `pip install pydantic[email]`')
@@ -140,7 +140,7 @@ class UrlStr(str):
     require_tld = True  # whether to reject non-FQDN hostnames
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield not_none_validator
         yield str_validator
         yield anystr_strip_whitespace
@@ -192,7 +192,7 @@ class NameEmail:
         self.email = email
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         if email_validator is None:
             raise ImportError('email-validator is not installed, run `pip install pydantic[email]`')
 
@@ -214,7 +214,7 @@ class PyObject:
     validate_always = True
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield str_validator
         yield cls.validate
 
@@ -233,7 +233,7 @@ class DSN(str):
     validate_always = True
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield str_validator
         yield cls.validate
 
@@ -268,7 +268,7 @@ class ConstrainedInt(int, metaclass=ConstrainedNumberMeta):
     le: Optional[int] = None
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield int_validator
         yield number_size_validator
 
@@ -294,7 +294,7 @@ class ConstrainedFloat(float, metaclass=ConstrainedNumberMeta):
     le: Union[None, int, float] = None
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield float_validator
         yield number_size_validator
 
@@ -322,7 +322,7 @@ class ConstrainedDecimal(Decimal, metaclass=ConstrainedNumberMeta):
     decimal_places: Optional[int] = None
 
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield not_none_validator
         yield decimal_validator
         yield number_size_validator
@@ -389,7 +389,7 @@ class UUID5(UUID):
 
 class FilePath(Path):
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield path_validator
         yield path_exists_validator
         yield cls.validate
@@ -404,7 +404,7 @@ class FilePath(Path):
 
 class DirectoryPath(Path):
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield path_validator
         yield path_exists_validator
         yield cls.validate
@@ -428,7 +428,7 @@ class JsonMeta(type):
 
 class Json(metaclass=JsonMeta):
     @classmethod
-    def get_validators(cls):
+    def __get_validators__(cls):
         yield str_validator
         yield cls.validate
 

tests/test_edge_cases.py

@@ -5,7 +5,7 @@ from typing import Any, Dict, List, Optional, Set, Tuple, Union
 
 import pytest
 
-from pydantic import BaseConfig, BaseModel, NoneStrBytes, StrBytes, ValidationError, constr, validate_model
+from pydantic import BaseConfig, BaseModel, NoneStrBytes, StrBytes, ValidationError, constr, errors, validate_model
 
 
 def test_str_bytes():
@@ -546,3 +546,48 @@ def test_optional_required():
     assert Model(bar=123).dict() == {'bar': 123}
     assert Model().dict() == {'bar': None}
     assert Model(bar=None).dict() == {'bar': None}
+
+
+def test_invalid_validator():
+    class InvalidValidator:
+        @classmethod
+        def __get_validators__(cls):
+            yield cls.has_wrong_arguments
+
+        @classmethod
+        def has_wrong_arguments(cls, value, bar):
+            pass
+
+    with pytest.raises(errors.ConfigError) as exc_info:
+
+        class InvalidValidatorModel(BaseModel):
+            x: InvalidValidator = ...
+
+    assert exc_info.value.args[0].startswith('Invalid signature for validator')
+
+
+def test_unable_to_infer():
+    with pytest.raises(errors.ConfigError) as exc_info:
+
+        class InvalidDefinitionModel(BaseModel):
+            x = None
+
+    assert exc_info.value.args[0] == 'unable to infer type for attribute "x"'
+
+
+def test_get_validator():
+    class CustomClass:
+        @classmethod
+        def get_validators(cls):
+            yield cls.validate
+
+        @classmethod
+        def validate(cls, v):
+            return v * 2
+
+    with pytest.warns(DeprecationWarning):
+
+        class Model(BaseModel):
+            x: CustomClass
+
+    assert Model(x=42).x == 84

tests/test_main.py

@@ -3,7 +3,7 @@ from typing import Any, List
 
 import pytest
 
-from pydantic import BaseModel, NoneBytes, NoneStr, Required, ValidationError, constr, errors
+from pydantic import BaseModel, NoneBytes, NoneStr, Required, ValidationError, constr
 
 
 def test_success():
@@ -159,34 +159,6 @@ def test_prevent_extra_fails():
     ]
 
 
-class InvalidValidator:
-    @classmethod
-    def get_validators(cls):
-        yield cls.has_wrong_arguments
-
-    @classmethod
-    def has_wrong_arguments(cls, value, bar):
-        pass
-
-
-def test_invalid_validator():
-    with pytest.raises(errors.ConfigError) as exc_info:
-
-        class InvalidValidatorModel(BaseModel):
-            x: InvalidValidator = ...
-
-    assert exc_info.value.args[0].startswith('Invalid signature for validator')
-
-
-def test_unable_to_infer():
-    with pytest.raises(errors.ConfigError) as exc_info:
-
-        class InvalidDefinitionModel(BaseModel):
-            x = None
-
-    assert exc_info.value.args[0] == 'unable to infer type for attribute "x"'
-
-
 def test_not_required():
     class Model(BaseModel):
         a: float = None