TypeError: stat: path should be string, bytes, os.PathLike or integer, not NoneType about refextract

[michamos]

Hi, it would be useful if you could provide the full traceback, rather than only the error at the end.

[walter-hernandez]

@tiffsea refextract uses pdftotext in the background. The error seems to be because refextract cannot find pdftotext installed in your system. Try installing it following the instructions for os dependencies here:

https://pypi.org/project/pdftotext/

and installing pdftotext:
pip install pdftotext

as well as:
conda install -c conda-forge poppler

The above solved the issue for me

[robinjacobroy]

@tiffsea To my limited knowledge, pip install pdftotext installs some other package, which is different from what is needed here (correct me if i am wrong). pdftotext(1) version 3.00 is to be installed for refextract.
So, i installed XpdfReader instead (https://www.xpdfreader.com/pdftotext-man.html) using the commands:

wget http://security.ubuntu.com/ubuntu/pool/main/p/poppler/libpoppler73_0.62.0-2ubuntu2.12_amd64.deb
sudo apt-get install ./libpoppler73_0.62.0-2ubuntu2.12_amd64.deb 
wget http://archive.ubuntu.com/ubuntu/pool/universe/x/xpdf/xpdf_3.04-7_amd64.deb 
sudo apt-get install ./xpdf_3.04-7_amd64.deb 

(ref: https://askubuntu.com/questions/1245518/how-to-install-xpdf-on-ubuntu-20-04)

The above solved the issue for me.