fix: preserve non-object response error bodies

ollama/_types.py

@@ -638,7 +638,9 @@ def __init__(self, error: str, status_code: int = -1):
     # try to parse content as JSON and extract 'error'
     # fallback to raw content if JSON parsing fails
     with contextlib.suppress(json.JSONDecodeError):
-      error = json.loads(error).get('error', error)
+      parsed_error = json.loads(error)
+      if isinstance(parsed_error, dict):
+        error = parsed_error.get('error', error)
 
     super().__init__(error)
     self.error = error

tests/test_type_serialization.py

@@ -4,7 +4,7 @@
 
 import pytest
 
-from ollama._types import CreateRequest, Image
+from ollama._types import CreateRequest, Image, ResponseError
 
 
 def test_image_serialization_bytes():
@@ -92,3 +92,15 @@ def test_create_request_serialization_license_list():
   request = CreateRequest(model='test-model', license=['MIT', 'Apache-2.0'])
   serialized = request.model_dump()
   assert serialized['license'] == ['MIT', 'Apache-2.0']
+
+
+def test_response_error_uses_json_object_error_field():
+  error = ResponseError('{"error": "model not found"}', 404)
+  assert error.error == 'model not found'
+  assert str(error) == 'model not found (status code: 404)'
+
+
+def test_response_error_preserves_non_object_json_body():
+  error = ResponseError('"server unavailable"', 503)
+  assert error.error == '"server unavailable"'
+  assert str(error) == '"server unavailable" (status code: 503)'