# Text Classification tokenizer problems on inference
**URL:**
**Author:**  [@lfcc](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Flfcc)%5C
**Post date:** [May 7, 2022, 6:49pm UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ftext-classification-tokenizer-problems-on-inference%2F17648%2F1 "2022-05-07T18:49:58Z")
I just finned tunned a BERT model for text classification (NER), it works great!
However, I found some nuances associated with the tokenizer, i.e., when I use my model for inference, the resultant entities come with “#” due to the subword tokenizer I suppose.
In order to fix this, I used the `"aggregation_strategy"` parameter. This parameter can receive 5 different values: none, simple, first, average and max. When I use “None” or “simple” the code runs well but I still get the result as subwords with “#”. If i try to use " first, average or max" options, I get the following error:
```auto
word_entities.append(self.aggregate_word(word_group, aggregation_strategy))
Python\Python39\lib\site-packages\transformers\pipelines\token_classification.py", line 336, in aggregate_word
word = self.tokenizer.convert_tokens_to_string([entity["word"] for entity in entities])
TypeError: 'NoneType' object is not iterable
```
Any idea how to fix this?
thank you
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**Author:**  [@ibrahimishag](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fibrahimishag)%5C
**Post date:** [October 12, 2022, 4:07am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ftext-classification-tokenizer-problems-on-inference%2F17648%2F2 "2022-10-12T04:07:05Z")
Hello, I ran into the same error!. I hope you found a way around it!..
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**Author:**  [@lfcc](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Flfcc)%5C
**Post date:** [October 12, 2022, 7:05am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ftext-classification-tokenizer-problems-on-inference%2F17648%2F3 "2022-10-12T07:05:10Z")
No, I did not.
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**Author:**  [@ibrahimishag](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fibrahimishag)%5C
**Post date:** [October 12, 2022, 7:57am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ftext-classification-tokenizer-problems-on-inference%2F17648%2F4 "2022-10-12T07:57:24Z")
Luckily for me, I found that one of the input sentences was none. Therefoere, I have preprocessed the input sentence by replacing the empty lines with dummy text and it worked!.
Thanks for raising the issue and for your immediate respone!.
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**Author:**  [@lfcc](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Flfcc)%5C
**Post date:** [October 12, 2022, 8:38am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Ftext-classification-tokenizer-problems-on-inference%2F17648%2F5 "2022-10-12T08:38:58Z")
Ho yeah!
I remember now, that was the problem. I had some NONE inputs as well, you are right.
Removing them was the solution.