Install on ubuntu 20.04 ModuleNotFoundError: No module named 'Cython'

[ahopejasen]

Issue happened while pip3 install -r requirements.txt was building scikit-learn

Issue was fixed with a manual install of cython: pip3 install cython, which installed cython Version: 0.29.17

I had previously installed numpy, pandas, matplotlib and others via ubuntu's apt package manager, if that makes a difference.

Python 3.8.2 pip 20.0.2 (python 3.8)

Full list of python packages installed after the error and immediately after I manually installed cython, but before successfully installing pyAudioAnalysis: https://pastebin.com/7rTDVMQQ

Hope that helps.

[slowglow]

This seems to be caused by outdated packages in requirements.txt. Particularly the hmmlearn package causes trouble by requiring other packages (numpy, scipy and scikit-learn) to also be lower version, than what might be installed in the system. One of them requires cython. Before you ask about virtual environment install, I tried it, but for some reason installation failed. What worked for me, was to remove the version numbers from the requirements.txt and install the latest non-conflicting versions of the required packages. So far, I haven't seen any problems or version conflicts with that.

May be it is time to review the requirements.txt and, if not proven really necessary, to remove the version requirements. At least updating the versions to more modern packages will ease the installation for many who are migrating and building a development environment around Python 3.8.