Jupyter Notebook ModuleNotFoundError

Maria_Adriana_Sabia · July 9, 2021, 2:00pm

Hello , I am trying to import ROOT on a Jupiter notebook but I get the following error:
ModuleNotFoundError: No module named ‘libROOTPythonizations3_8’. Have you got any idea on how to solve it ?

_ROOT Version: 6.22.02
_Platform: MacOS
_Compiler:g++

couet · July 9, 2021, 2:21pm

@etejedor may help you.

etejedor · July 9, 2021, 2:36pm

Hello,

It looks like the PyROOT in your ROOT installation was not compiled for Python3.8.

Could you check what python version is supported by your ROOT with:

root-config --python-version
root-config --python2-version
root-config --python3-version

Maria_Adriana_Sabia · July 9, 2021, 2:37pm

2.7.16
2.7.16
2.7.16

etejedor · July 9, 2021, 2:49pm

It seems then that your ROOT installation has only been built for Python2.7.16. When starting Jupyter, please make sure you use a Python2 Jupyter kernel (the one you are using now seems to be Python3.8).

Maria_Adriana_Sabia · July 9, 2021, 2:53pm

I have tried but it gives me another error:
ImportError: No module named ROOT

etejedor · July 9, 2021, 3:00pm

This other error indicates that Python does not find the ROOT module. For that purpose, please do source $ROOTSYS/bin/thisroot.sh, where $ROOTSYS is your ROOT installation dir, and then from the same terminal session run jupyter again.

Maria_Adriana_Sabia · July 9, 2021, 3:10pm

Done! It gives me :
ModuleNotFoundError: No module named ‘libROOTPythonizations3_8’

etejedor · July 9, 2021, 3:23pm

That’s the first error you reported, please make sure the Jupyter kernel that runs is Python2.

Maria_Adriana_Sabia · July 9, 2021, 3:33pm

If I run Jupiter from the same session the kernel is automatically python3

etejedor · July 9, 2021, 3:36pm

You don’t have the python2 Jupyter kernel installed. You need to run, for example:

python2 -m pip install ipykernel

Maria_Adriana_Sabia · July 9, 2021, 3:37pm

I got that all the requirements are already satisfied

etejedor · July 9, 2021, 3:52pm

Does

jupyter kernelspec list

list your Python2 kernel? If not, you need to make sure it’s installed and Jupyter sees it.

Maria_Adriana_Sabia · July 9, 2021, 4:09pm

No it is not but I don’t know how to be sure that Jupyter sees it

etejedor · July 9, 2021, 5:29pm

Please check the Jupyter docs for installing kernels:

https://jupyter.readthedocs.io/en/latest/install/kernels.html

Maria_Adriana_Sabia · July 9, 2021, 5:47pm

I have now installed python 2 and the error is:
ImportError Traceback (most recent call last)
in ()
----> 1 import ROOT

/Applications/root_v6.22.02/lib/ROOT/init.py in ()
26 environ[‘CPPYY_NO_ROOT_FILTER’] = ‘1’
27
—> 28 import cppyy
29
30 # import libROOTPythonizations with Python version number

ImportError: No module named cppyy

etejedor · July 12, 2021, 6:57am

Hello,
This is probably another problem in the environment that you are using - looks like some problem with the ROOT installation this time, since cppyy should definitely be there.

May I suggest to install and use ROOT via conda? That way the environment you’ll use will be more under control: