# How can I specify the python version to use/install ? (system and hub is 3.10, while user is 3.9)

**URL:** <https://discourse.jupyter.org/t/how-can-i-specify-the-python-version-to-use-install-system-and-hub-is-3-10-while-user-is-3-9/15763>\
**Category:** The Littlest JupyterHub\
**Created:** [September 13, 2022, 3:09am UTC](https://discourse.jupyter.org/t/how-can-i-specify-the-python-version-to-use-install-system-and-hub-is-3-10-while-user-is-3-9/15763 "2022-09-13T03:09:26Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![mtav](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/mtav/32/7899_2.png) [@mtav](https://discourse.jupyter.org/u/mtav)\
**Post date:** [September 13, 2022, 3:09am UTC](https://discourse.jupyter.org/t/how-can-i-specify-the-python-version-to-use-install-system-and-hub-is-3-10-while-user-is-3-9/15763/1 "2022-09-13T03:09:26Z")

</div>

After installing tljh via:

```auto
curl -L https://tljh.jupyter.org/bootstrap.py \
  | sudo python3 - \
    --admin admin:PASSWORD

```

my jupyter notebooks all use python 3.9, even though my system python was 3.10 and it looks like 3.10 is also used by the hub:

```auto
$ python3 --version
Python 3.10.4
$ ls /opt/tljh/hub/lib/
python3.10
$ source /opt/tljh/user/bin/activate
(base) $ python3 --version
Python 3.9.7

```

How can I make the jupyter notebooks use 3.10 or even my system python directly?  
Using my system python would make things easier as I managed to install all the packages I need successfully there.

I tried following the steps in the official documentation, as well as the fixes suggested [here](https://github.com/jupyterhub/the-littlest-jupyterhub/issues/824), but both give me errors.

**Background:**

More specifically, I am trying to set up a jupyterhub for [meep and mpb](https://meep.readthedocs.io/en/latest/Installation/#conda-packages) with:

```auto
conda install -c conda-forge pymeep pymeep-extras
# or for tljh:
# sudo env PATH=${PATH} conda install -c conda-forge pymeep pymeep-extras

```

This command works for me in a miniconda install, but not in the tljh jupyter notebooks.  
Or rather, it seems to work, but the following essential imports then fail in python scripts:

```auto
import h5py
from meep import mpb

```

They fail with:

```auto
>>> import h5py
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/tljh/user/lib/python3.9/site-packages/h5py/ __init__.py", line 33, in <module>
    from . import version
  File "/opt/tljh/user/lib/python3.9/site-packages/h5py/version.py", line 15, in <module>
    from . import h5 as _h5
  File "h5py/h5.pyx", line 1, in init h5py.h5
ImportError: /opt/tljh/user/lib/python3.9/site-packages/h5py/defs.cpython-39-x86_64-linux-gnu.so: undefined symbol: H5Pget_fapl_direct
>>> from meep import mpb
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/tljh/user/lib/python3.9/site-packages/meep/mpb/ __init__.py", line 355, in <module>
    from .solver import (
  File "/opt/tljh/user/lib/python3.9/site-packages/meep/mpb/solver.py", line 10, in <module>
    import h5py
  File "/opt/tljh/user/lib/python3.9/site-packages/h5py/ __init__.py", line 33, in <module>
    from . import version
  File "/opt/tljh/user/lib/python3.9/site-packages/h5py/version.py", line 15, in <module>
    from . import h5 as _h5
  File "h5py/h5.pyx", line 1, in init h5py.h5
ImportError: /opt/tljh/user/lib/python3.9/site-packages/h5py/defs.cpython-39-x86_64-linux-gnu.so: undefined symbol: H5Pget_fapl_direct

```

In my miniconda install, it works fine.

---

<div class="post-metadata">

**Author:** ![mtav](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.jupyter.org/mtav/32/7899_2.png) [@mtav](https://discourse.jupyter.org/u/mtav)\
**Post date:** [September 13, 2022, 6:01pm UTC](https://discourse.jupyter.org/t/how-can-i-specify-the-python-version-to-use-install-system-and-hub-is-3-10-while-user-is-3-9/15763/2 "2022-09-13T18:01:28Z")

</div>

I decided to focus on creating a new conda environment with a newer python version, which turned out to be easier.

Doing it system-wide as admin was a bit trickier, but here is a script that sets up a new “photonics” environment with meep and mpb installed:

```auto
#!/bin/bash
set -eu
# shows up in conda env list
MYENV_CONDANAME="photonics"
# shows up in the jupyter kernel list
MYENV_JUPYTERNAME="photonics"

# activate environment
source /opt/tljh/user/bin/activate
# list current environments
conda env list

set +e
# remove any previous installation
sudo env PATH=${PATH} jupyter kernelspec uninstall "${MYENV_JUPYTERNAME}" -y
sudo env PATH=${PATH} conda env remove -n "${MYENV_CONDANAME}"
set -e

# create new environment
sudo env PATH=${PATH} conda create -n "${MYENV_CONDANAME}" python=3.10 --yes
# activate it
conda activate "${MYENV_CONDANAME}"
# install ipykernel
sudo env PATH=${PATH} CONDA_DEFAULT_ENV="${MYENV_CONDANAME}" conda install ipykernel --yes
# make available in jupyter
sudo env PATH=${PATH} CONDA_DEFAULT_ENV="${MYENV_CONDANAME}" ipython kernel install --name="${MYENV_JUPYTERNAME}"
# install meep/mpb
sudo env PATH=${PATH} CONDA_DEFAULT_ENV="${MYENV_CONDANAME}" conda install -c conda-forge pymeep pymeep-extras --yes

# list current environments
conda env list

# check it worked
jupyter kernelspec list

# # deactivate conda env
# source /opt/tljh/user/bin/activate
# conda activate adminpython
# source /opt/tljh/user/bin/activate
# conda deactivate

echo "Environment successfully added."

```