Using lgbm pipeline model for house price prediction in web app

Hello everyone, I trained a LGBM model (pipeline-based) for house price prediction. When I use the saved model in google colab for predicting the price of a new house, it works fine. But when I use it in sreamlit, it returns an error. The error seems to be related to creating the dataframe of the new house features. I have searched and tried different solutions but each one returns an error, while the same code in colab is works fine.

The files are available on my Github:

Training and saving the LGBM model: “Copy of HousePricePrediction.ipynb”
The model: “finalized_pipeline_model.joblib”
Using the model in colab: “newHousePrediction.ipynb”
Using the model in streamlit: “”
requirements: “req.txt”


ValueError: All arrays must be of the same length


File "C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\streamlit\scriptrunner\", line 557, in _run_script
    exec(code, module.__dict__)File "", line 30, in <module>
    X = pd.DataFrame(output)
        ^^^^^^^^^^^^^^^^^^^^File "C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\pandas\core\", line 767, in __init__
    mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^File "C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\pandas\core\internals\", line 503, in dict_to_mgr
    return arrays_to_mgr(arrays, columns, index, dtype=dtype, typ=typ, consolidate=copy)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^File "C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\pandas\core\internals\", line 114, in arrays_to_mgr
    index = _extract_index(arrays)
            ^^^^^^^^^^^^^^^^^^^^^^File "C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\pandas\core\internals\", line 677, in _extract_index
    raise ValueError("All arrays must be of the same length")

Use selectbox instead of multiselect. this way the value of address is single or scalar and not a list and also the first value of address is at index 0 of the option.

Address = st.selectbox("Address", address)

Then revise the output as well. Put Address under the bracket.

output = {'Area':[Area], 'Room':[Room], 'Parking':[Parking],
          'Warehouse':[Warehouse], 'Elevator':[Elevator], 'Address':[Address]}

Thanks for your reply. I did that, but when the dataframe is passed to the model, this error is returned:

AttributeError: ‘str’ object has no attribute ‘transform’


File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\streamlit\scriptrunner\”, line 557, in _run_script
exec(code, module.dict)
File “”, line 34, in
predictionX = model.predict(X)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\”, line 602, in predict
Xt = transform.transform(Xt)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\”, line 295, in wrapped
data_to_wrap = f(self, X, *args, **kwargs)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\”, line 1014, in transform
Xs = self._call_func_on_transformers(
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\”, line 823, in _call_func_on_transformers
return Parallel(n_jobs=self.n_jobs)(jobs)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\utils\”, line 67, in call
return super().call(iterable_with_config)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\joblib\”, line 1863, in call
return output if self.return_generator else list(output)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\joblib\”, line 1792, in _get_sequential_output
res = func(*args, **kwargs)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\utils\”, line 129, in call
return self.function(*args, **kwargs)
File “C:\Users\b_sad\anaconda3\envs\test\Lib\site-packages\sklearn\”, line 1283, in _transform_one
res = transformer.transform(X, **params.transform)

In the pipeline, I used make_column_transformer, in which oneHotEncoder is applied on the address column. Is the error related to this part? What should I do?
The pipeline is available in this file: “PipelineModel.ipynb”

That is another issue.

Your issue is ValueError: All arrays must be of the same length. And you are using multiselect.

Create another post, for new issue.

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Thank you :pray:

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