Improve Pydantic v1/2 cross-compatibility (#101)

---------

Co-authored-by: Charles Tapley Hoyt <[email protected]>

src/curies/_pydantic_compat.py

@@ -0,0 +1,24 @@
+"""A compatibility layer for pydantic 1 and 2."""
+
+from pydantic import __version__ as pydantic_version
+
+__all__ = [
+    "PYDANTIC_V1",
+    "field_validator",
+    "get_field_validator_values",
+]
+
+PYDANTIC_V1 = pydantic_version.startswith("1.")
+
+if PYDANTIC_V1:
+    from pydantic import validator as field_validator
+else:
+    from pydantic import field_validator
+
+
+def get_field_validator_values(values, key: str):  # type:ignore
+    """Get the value for the key from a field validator object, cross-compatible with Pydantic 1 and 2."""
+    if PYDANTIC_V1:
+        return values[key]
+    else:
+        return values.data[key]

src/curies/api.py

@@ -33,9 +33,11 @@
 )
 
 import requests
-from pydantic import BaseModel, Field, validator
+from pydantic import BaseModel, Field
 from pytrie import StringTrie
 
+from ._pydantic_compat import field_validator, get_field_validator_values
+
 if TYPE_CHECKING:  # pragma: no cover
     import pandas
     import rdflib
@@ -267,18 +269,18 @@ class Records(BaseModel):
         "Warning: this is an experimental feature.",
     )
 
-    @validator("prefix_synonyms")  # type:ignore
+    @field_validator("prefix_synonyms")  # type:ignore
     def prefix_not_in_synonyms(cls, v: str, values: Mapping[str, Any]) -> str:  # noqa:N805
         """Check that the canonical prefix does not apper in the prefix synonym list."""
-        prefix = values["prefix"]
+        prefix = get_field_validator_values(values, "prefix")
         if prefix in v:
             raise ValueError(f"Duplicate of canonical prefix `{prefix}` in prefix synonyms")
         return v
 
-    @validator("uri_prefix_synonyms")  # type:ignore
+    @field_validator("uri_prefix_synonyms")  # type:ignore
     def uri_prefix_not_in_synonyms(cls, v: str, values: Mapping[str, Any]) -> str:  # noqa:N805
         """Check that the canonical URI prefix does not apper in the URI prefix synonym list."""
-        uri_prefix = values["uri_prefix"]
+        uri_prefix = get_field_validator_values(values, "uri_prefix")
         if uri_prefix in v:
             raise ValueError(
                 f"Duplicate of canonical URI prefix `{uri_prefix}` in URI prefix synonyms"