pylock: make internal exception class private

This was not meant to be public

Author: sbidoul

src/packaging/pylock.py

@@ -96,7 +96,7 @@ def _get(d: Mapping[str, Any], expected_type: type[_T], key: str) -> _T | None:
 def _get_required(d: Mapping[str, Any], expected_type: type[_T], key: str) -> _T:
     """Get a required value from the dictionary and verify it's the expected type."""
     if (value := _get(d, expected_type, key)) is None:
-        raise PylockRequiredKeyError(key)
+        raise _PylockRequiredKeyError(key)
     return value
 
 
@@ -150,7 +150,7 @@ def _get_required_as(
     """Get a required value from the dict, verify it's the expected type,
     and convert to the target type."""
     if (value := _get_as(d, expected_type, target_type, key)) is None:
-        raise PylockRequiredKeyError(key)
+        raise _PylockRequiredKeyError(key)
     return value
 
 
@@ -209,7 +209,7 @@ def _get_required_sequence_of_objects(
     """Get a required list value from the dictionary and convert its items to a
     dataclass."""
     if (result := _get_sequence_of_objects(d, target_item_type, key)) is None:
-        raise PylockRequiredKeyError(key)
+        raise _PylockRequiredKeyError(key)
     return result
 
 
@@ -263,7 +263,7 @@ def __str__(self) -> str:
         return self.message
 
 
-class PylockRequiredKeyError(PylockValidationError):
+class _PylockRequiredKeyError(PylockValidationError):
     def __init__(self, key: str) -> None:
         super().__init__("Missing required value", context=key)
 

tests/test_pylock.py

@@ -15,7 +15,6 @@
     PackageVcs,
     PackageWheel,
     Pylock,
-    PylockRequiredKeyError,
     PylockUnsupportedVersionError,
     PylockValidationError,
     is_valid_pylock_path,
@@ -104,7 +103,7 @@ def test_pylock_missing_version() -> None:
         "created-by": "pip",
         "packages": [],
     }
-    with pytest.raises(PylockRequiredKeyError) as exc_info:
+    with pytest.raises(PylockValidationError) as exc_info:
         Pylock.from_dict(data)
     assert str(exc_info.value) == "Missing required value in 'lock-version'"
 
@@ -114,7 +113,7 @@ def test_pylock_missing_created_by() -> None:
         "lock-version": "1.0",
         "packages": [],
     }
-    with pytest.raises(PylockRequiredKeyError) as exc_info:
+    with pytest.raises(PylockValidationError) as exc_info:
         Pylock.from_dict(data)
     assert str(exc_info.value) == "Missing required value in 'created-by'"
 
@@ -124,7 +123,7 @@ def test_pylock_missing_packages() -> None:
         "lock-version": "1.0",
         "created-by": "uv",
     }
-    with pytest.raises(PylockRequiredKeyError) as exc_info:
+    with pytest.raises(PylockValidationError) as exc_info:
         Pylock.from_dict(data)
     assert str(exc_info.value) == "Missing required value in 'packages'"