tensorflow/models · error · ValueError

For training, each question should have exactly 1 answer.

Error message

For training, each question should have exactly 1 answer.

What it means

Error "For training, each question should have exactly 1 answer." thrown in tensorflow/models.

Source

Thrown at official/nlp/data/squad_lib.py:210

            doc_tokens.append(c)
          else:
            doc_tokens[-1] += c
          prev_is_whitespace = False
        char_to_word_offset.append(len(doc_tokens) - 1)

      for qa in paragraph["qas"]:
        qas_id = qa["id"]
        question_text = qa["question"]
        start_position = None
        end_position = None
        orig_answer_text = None
        is_impossible = False
        if is_training:

          if version_2_with_negative:
            is_impossible = qa["is_impossible"]
          if (len(qa["answers"]) != 1) and (not is_impossible):
            raise ValueError(
                "For training, each question should have exactly 1 answer.")
          if not is_impossible:
            answer = qa["answers"][0]
            orig_answer_text = answer["text"]
            answer_offset = answer["answer_start"]
            answer_length = len(orig_answer_text)
            start_position = char_to_word_offset[answer_offset]
            end_position = char_to_word_offset[answer_offset + answer_length -
                                               1]
            # Only add answers where the text can be exactly recovered from the
            # document. If this CAN'T happen it's likely due to weird Unicode
            # stuff so we will just skip the example.
            #
            # Note that this means for training mode, every example is NOT
            # guaranteed to be preserved.
            actual_text = " ".join(doc_tokens[start_position:(end_position +
                                                              1)])
            cleaned_answer_text = " ".join(

View on GitHub (pinned to e006f5f0d5)

When it happens

Trigger: Thrown at official/nlp/data/squad_lib.py:210 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of tensorflow/models@e006f5f0d5 (2026-08-24). Data as JSON: /api/errors/2b13d19033c0a12e. Report an issue: GitHub.