feat: add v1 namespace (#8)

* feat: add v1 namespace

* add test

* back to star

* update module doc

src/pydantic_compat/__init__.py

@@ -26,6 +26,7 @@
     "BaseModel",
 ]
 
+
 from ._shared import PYDANTIC2
 
 if TYPE_CHECKING:

src/pydantic_compat/v1.py

@@ -0,0 +1,16 @@
+"""This module is a try/except pass-through for the pydantic.v1 namespace.
+
+The pydantic.v1 namespace was added in pydantic v2.  It contains the entire
+pydantic v1 package.  For packages that would like to unpin their 'pydantic<2'
+dependency *without* needing to update all of their code to use the pydantic v2 api,
+this provides a simple way to delay that update.
+
+This is different from the goal of pydantic_compat on the whole, which is to provide
+an API translation layer that allows you to actually use pydantic v2 features
+(e.g. rust-backed speed, etc...) while also being compatible with packages that pin
+pydantic<2.
+"""
+try:
+    from pydantic.v1 import *  # noqa
+except ImportError:
+    from pydantic import *  # type: ignore # noqa

tests/test_base_model.py

@@ -118,3 +118,13 @@ class Model(PydanticCompatMixin, pydantic.BaseModel):
     # test extra
     with pytest.raises((ValueError, TypeError)):  # (v1, v2)
         Model(extra=1)
+
+
+def test_v1_namespace() -> None:
+    from pydantic_compat.v1 import BaseModel
+
+    class Model(BaseModel):
+        x: int = 1
+
+    m = Model()
+    assert m.dict() == {"x": 1}  # no warning