Simply add python modules

ParaView Support
1

Hi everyone.

I’d like to add pyarrow to pvpython so that it can read/write .parquet files.
I managed on my local machine, but had to go through the quite tedious method of building paraview from scratch.

I’d like to know, since I want to share my code using .parquet with others, if there is a more straightforward way?
I did find that using virtual environment could help, as explained here: https://www.kitware.com/using-pvpython-and-virtualenv/

The issue is that I seem to have conflict when I do so using the paraview version from the website. When I build my environment and then use the commands:

vEnv='/home/environments/paraview_env/bin/activate_this.py'
exec(open(vEnv).read(), {'__file__': vEnv})

Then it seems like simple libraries as numpy wont work anymore, with error as such as:

>>> import pandas as pd
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/boris/environments/paraview_env/lib/python3.10/site-packages/pandas/__init__.py", line 22, in <module>
    from pandas.compat import is_numpy_dev as _is_numpy_dev  # pyright: ignore # noqa:F401
  File "/home/boris/environments/paraview_env/lib/python3.10/site-packages/pandas/compat/__init__.py", line 18, in <module>
    from pandas.compat.numpy import (
  File "/home/boris/environments/paraview_env/lib/python3.10/site-packages/pandas/compat/numpy/__init__.py", line 4, in <module>
    from pandas.util.version import Version
  File "/home/boris/environments/paraview_env/lib/python3.10/site-packages/pandas/util/__init__.py", line 2, in <module>
    from pandas.util._decorators import (  # noqa:F401
  File "/home/boris/environments/paraview_env/lib/python3.10/site-packages/pandas/util/_decorators.py", line 14, in <module>
    from pandas._libs.properties import cache_readonly
  File "/home/boris/environments/paraview_env/lib/python3.10/site-packages/pandas/_libs/__init__.py", line 13, in <module>
    from pandas._libs.interval import Interval
ModuleNotFoundError: No module named 'pandas._libs.interval'

Meanwhile, if I import pandas without the venv, it works… Any clue, or other way of importing my modules?

Thank you!

2

Not sure that is the issue here but you are using Python 3.10 while ParaView is using Python 3.9.

For your venv you need to have a version match.

3

Thanks for the idea.

I tried with python 3.9 virtualenv, same issue. And I also get this issue on windows OS.

To use virtual env, is it needed to have a self-compiled version? Or the installer from the website should be enough?

EDIT: Actually, for windows it works. No idea what was wrong the first time. For future readers, what I did is the following:

0- Download and install python 3.9
1- Create a virtualenv and install pyarrow and fastparquet. To do so, use the command like

python -m virtualenv -p="C:\Users\YourPath\AppData\Local\Programs\Python\Python39\python.exe" "Path/to/venv"

2- Then, simply activate the script (.\Scripts\Activate.ps1 for powershell) and install your libraries
3- Now, create an environment variable called PV_VENV, and of value the path to your venv folder.
4- You can check that the venv is indeed used through the python command inside paraview : from paraview.web import venv

Probably the commands from my first post also works, instead of the PV_VENV.

Regarding why it does not work on ubuntu, I will try to look further into it.