Fixed deserialized computed fields issue (#233)

paperqa/types.py

@@ -1,7 +1,14 @@
 from typing import Any, Callable
 from uuid import UUID, uuid4
 
-from pydantic import BaseModel, ConfigDict, Field, computed_field, field_validator
+from pydantic import (
+    BaseModel,
+    ConfigDict,
+    Field,
+    computed_field,
+    field_validator,
+    model_validator,
+)
 
 from .prompts import (
     citation_prompt,
@@ -169,12 +176,19 @@ class Answer(BaseModel):
     cost: float | None = None
     # key is model name, value is (prompt, completion) token counts
     token_counts: dict[str, list[int]] = Field(default_factory=dict)
-    model_config = ConfigDict(extra="forbid")
+    model_config = ConfigDict(extra="ignore")
 
     def __str__(self) -> str:
         """Return the answer as a string."""
         return self.formatted_answer
 
+    @model_validator(mode="before")
+    @classmethod
+    def remove_computed(cls, data: Any) -> Any:
+        if isinstance(data, dict):
+            data.pop("used_contexts", None)
+        return data
+
     @computed_field  # type: ignore
     @property
     def used_contexts(self) -> set[str]:

paperqa/version.py

@@ -1 +1 @@
-__version__ = "4.0.0-pre.6"
+__version__ = "4.0.0-pre.7"

tests/test_paperqa.py

@@ -552,6 +552,10 @@ def test_answer_attributes():
     js = answer.model_dump_json()
     assert "used_contexts" in js
 
+    # make sure it can be deserialized
+    answer2 = Answer.model_validate_json(js)
+    assert answer2.used_contexts == used_citations
+
 
 def test_llmresult_callbacks():
     my_results = []