String columns in dataframe not supported

[naitikbhise]

I am trying to use mlprodict to_onnx function to convert the string columns within a dataframe to onnx format. Working with sklearn-onnx convert_sklearn, the conversion to onnx works well. But I have another usecase and I prefer using the to_onnx .

The error I receive from the conversion is " NotImplementedError: Unsupported type '<class 'str'>'". So a string dataframe column is not converted to StringTensorType.

[xadupre]

Would it be possible to share an example of what you try to do. I'd like to make it available in sklearn-onnx instead and remove the need for this dependency.