Deprecate importing Validator from the package root.

Import it from jsonschema.protocols instead.

CHANGELOG.rst

@@ -1,3 +1,9 @@
+v4.19.0
+=======
+
+* Importing the ``Validator`` protocol directly from the package root is deprecated.
+  Import it from ``jsonschema.protocols.Validator`` instead.
+
 v4.18.6
 =======
 

jsonschema/__init__.py

@@ -13,7 +13,6 @@
 from jsonschema._format import FormatChecker
 from jsonschema._types import TypeChecker
 from jsonschema.exceptions import SchemaError, ValidationError
-from jsonschema.protocols import Validator
 from jsonschema.validators import (
     Draft3Validator,
     Draft4Validator,
@@ -65,6 +64,16 @@ def __getattr__(name):
         )
         from jsonschema.exceptions import FormatError
         return FormatError
+    elif name == "Validator":
+        warnings.warn(
+            "Importing Validator directly from the jsonschema package "
+            "is deprecated and will become an ImportError. Import it from "
+            "jsonschema.protocols instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        from jsonschema.protocols import Validator
+        return Validator
     elif name == "RefResolutionError":
         from jsonschema.exceptions import _RefResolutionError
         warnings.warn(
@@ -107,6 +116,5 @@ def __getattr__(name):
     "SchemaError",
     "TypeChecker",
     "ValidationError",
-    "Validator",
     "validate",
 ]

jsonschema/tests/test_deprecations.py

@@ -9,7 +9,7 @@
 
 import referencing.exceptions
 
-from jsonschema import FormatChecker, exceptions, validators
+from jsonschema import FormatChecker, exceptions, protocols, validators
 
 
 class TestDeprecations(TestCase):
@@ -64,6 +64,19 @@ def test_import_FormatError(self):
         self.assertEqual(FormatError, exceptions.FormatError)
         self.assertEqual(w.filename, __file__)
 
+    def test_import_Validator(self):
+        """
+        As of v4.19.0, importing Validator from the package root is
+        deprecated in favor of doing so from jsonschema.protocols.
+        """
+
+        message = "Importing Validator directly from the jsonschema package "
+        with self.assertWarnsRegex(DeprecationWarning, message) as w:
+            from jsonschema import Validator
+
+        self.assertEqual(Validator, protocols.Validator)
+        self.assertEqual(w.filename, __file__)
+
     def test_validators_validators(self):
         """
         As of v4.0.0, accessing jsonschema.validators.validators is