Error with line 'from py import path' in Field.py

[pierrick-giffard]

Hi,

I use Parcels 2.1.4 and I'm getting an error while importing Field at line 16: from py import path. Honestly, I didn't understand really what is the module py... I tried to create a new environment but I had the same problem. Thanks for your help,

Pierrick

Traceback (most recent call last):
File "/data/rd_exchange2/pgiffard/stamm/src/STAMM.py", line 15, in
from parcels import plotTrajectoriesFile,ErrorCode
File "/data/rd_exchange2/pgiffard/anaconda/envs/parcelstest/lib/python3.6/site-packages/parcels/init.py", line 4, in
from parcels.fieldset import * # noqa
File "/data/rd_exchange2/pgiffard/anaconda/envs/parcelstest/lib/python3.6/site-packages/parcels/fieldset.py", line 8, in
from parcels.field import Field, DeferredArray
File "/data/rd_exchange2/pgiffard/anaconda/envs/parcelstest/lib/python3.6/site-packages/parcels/field.py", line 16, in
from py import path
ModuleNotFoundError: No module named 'py'

[erikvansebille]

This seems a botched install. How did you install Parcels? Following the installation instructions on the oceanparcels.org website? Could you try again with a clean conda environment?

[pierrick-giffard]

Hi Erik,
In a terminal, I did:

conda create -n py3_parcels -c conda-forge python=3.6 parcels jupyter cartopy ffmpeg
conda activate py3_parcels
import parcels

And I still get the same error. I use conda 4.8.2. I tried with an other computer and still get the same error.

[erikvansebille]

Hmm, this is strange. I was indeed able to replicate your Error, but had not experienced this before. It might be because perhaps py is not default installed in the latest conda version 4.8.2 anymore?

Anyways, a simple solution is to do

conda install py

That fixes this Issue for me. Let us know if it works!

[willirath]

Note that according to https://github.com/pytest-dev/py, py is maintenance only and should be avoided for future projects. The authors of py suggest using pathlib from the standad library instead of py.path.

[erikvansebille]

Thanks for the update @willirath! I will then create a PR soon that phases out py; should not be too hard for Parcels

[pierrick-giffard]

Thanks @willirath and @erikvansebille , conda install py does the job for now.

[erikvansebille]

Fixed in #770