Repository: explodinggradients/ragas
Issue: faithfulness AttributeError: 'int' object has no attribute 'lower'
Root cause: Validation Gap

I am occasionally encountering an error when evaluating with faithfulness. 
ragas==0.1.4

Runner in Executor raised an exception
Traceback (most recent call last):
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\executor.py", line 79, in _aresults
    r = await future
        ^^^^^^^^^^^^
  File "C:\Python312\Lib\asyncio\tasks.py", line 621, in _wait_for_one
    return f.result()  # May raise f.exception().
           ^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\executor.py", line 38, in sema_coro
    return await coro
           ^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\executor.py", line 112, in wrapped_callable_async
    return counter, await callable(*args, **kwargs)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\base.py", line 93, in ascore
    raise e
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\base.py", line 89, in ascore
    score = await self._ascore(row=row, callbacks=group_cm, is_async=is_async)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\_faithfulness.py", line 201, in _ascore
    return self._compute_score(json_output)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\_faithfulness.py", line 155, in _compute_score
    faithful_statements = sum(
                          ^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\_faithfulness.py", line 157, in <genexpr>
    statement_with_validation.get("verdict", "").lower(), np.nan
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'int' object has no attribute 'lower'
Runner in Executor raised an exception
Traceback (most recent call last):
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\executor.py", line 79, in _aresults
    r = await future
        ^^^^^^^^^^^^
  File "C:\Python312\Lib\asyncio\tasks.py", line 621, in _wait_for_one
    return f.result()  # May raise f.exception().
           ^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\executor.py", line 38, in sema_coro
    return await coro
           ^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\executor.py", line 112, in wrapped_callable_async
    return counter, await callable(*args, **kwargs)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\base.py", line 93, in ascore
    raise e
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\base.py", line 89, in ascore
    score = await self._ascore(row=row, callbacks=group_cm, is_async=is_async)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\_faithfulness.py", line 201, in _ascore
    return self._compute_score(json_output)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\_faithfulness.py", line 155, in _compute_score
    faithful_statements = sum(
                          ^^^^
  File "D:\python_data\fuck\venv\Lib\site-packages\ragas\metrics\_faithfulness.py", line 157, in <genexpr>
    statement_with_validation.get("verdict", "").lower(), np.nan
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'int' object has no attribute 'lower'