numpy error in the latest parcels install

[JohannaWren]

Question

Question

Hi,

I just installed a new version of Parcels (I have been working with an old version for a while now) following the instructions using conda on the parcels site and while this install seemed to go well I keep getting the error "AttributeError: np.infty was removed in the NumPy 2.0 release. Use np.inf instead." when I try to import parcels into python. I went in and changed np.infty to np.inf in the files that were causing these issues (e.g. baseparticleset.py). It worked to a point (I was able to load a fieldset and particle set), but then Parcels wouldn't recognize a change I made to one file and kept throwing errors when I tried to execute the pset. So I removed the new parcels install and did a fresh one but the error persists. I get the error when running the peninsula example as well as my own code. I pasted the full error call below. I also at one point tried to install an older version of NumPy in the parcels environment, but then kept getting dependency errors from tons of other packages so that didn't seem like a viable solution either. My computer is a mac running Ventura. I was wondering if anyone else is getting the NumPy error, or if it's something unique to my system since it's older? And if folks are, is there a solution that doesn't require me going in and changing Parcels "source" code (i.e. code that parcels needs to run that came with the install)?

Thanks so much,
Johanna

Supporting code/error messages

(parcelsMay2025) jwren@PICSN79MAC parcels_tutorials (3.1.3.dev34) % python example_peninsula.py --fieldset 100 100
Traceback (most recent call last):
  File "/Users/jwren/Downloads/parcels_tutorials (3.1.3.dev34)/example_peninsula.py", line 9, in <module>
    import parcels
  File "/Users/jwren/miniconda3/envs/parcelsMay2025/lib/python3.11/site-packages/parcels/__init__.py", line 16, in <module>
    from parcels.particlefile import *  # noqa
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/jwren/miniconda3/envs/parcelsMay2025/lib/python3.11/site-packages/parcels/particlefile/__init__.py", line 3, in <module>
    from .baseparticlefile import BaseParticleFile  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/jwren/miniconda3/envs/parcelsMay2025/lib/python3.11/site-packages/parcels/particlefile/baseparticlefile.py", line 33, in <module>
    class BaseParticleFile(ABC):
  File "/Users/jwren/miniconda3/envs/parcelsMay2025/lib/python3.11/site-packages/parcels/particlefile/baseparticlefile.py", line 67, in BaseParticleFile
    def __init__(self, name, particleset, outputdt=np.infty, chunks=None, write_ondelete=False,
                                                   ^^^^^^^^
  File "/Users/jwren/miniconda3/envs/parcelsMay2025/lib/python3.11/site-packages/numpy/__init__.py", line 400, in __getattr__
    raise AttributeError(
AttributeError: `np.infty` was removed in the NumPy 2.0 release. Use `np.inf` instead.

[VeckoTheGecko]

I suspect you still have an older version of parcels as this issue (#1588) was patched in #1589.

If you type in your terminal conda env export you'll see the dependencies on your environment. What does it say for parcels?

Get the latest version of parcels (3.1.2) by running conda update -c conda-forge parcels

[JohannaWren]

Thank you for the quick reply! I assumed that a fresh parcels install would give me the most recent version, so I never checked the version. Turns out it installed parcels=2.4.2 because my version of conda was so old. Rookie mistake on my part. After a fresh conda install I was able to install parcels 3.1.2 and the peninsula example ran great. Thanks so much for your help!
~Johanna

[VeckoTheGecko]

because my version of conda was so old

Ah! Interesting - hearing this I think that it's because parcels now uses noarch to distribute on conda. Looking at the Conda Parcels listing we have v3.1.2 for noarch but v2.4.2 for the platform specific entries, but noarch is only supported from conda 4.3 it seems.

Perhaps this is worth us adding to an FAQ somewhere that people need conda >4.2...

[VeckoTheGecko]

@JohannaWren , from a user POV, how did you realise that it was a conda version issue? Did you try do conda install parcels==3.1.2 and it gave you an explainable error message about the conda version?

[JohannaWren]

I was getting a warning that my conda was not up to date when I tried to update parcels, but didn't think much of it until it wouldn't update parcels. So I did a general google search to figure out why a package wouldn't update through conda, and a lot of posts said it is likely a dependency/compatibility issue so to first try to update conda. So I tried that but since I was running such an old version (23.3.1) I couldn't update conda and had to do a fresh install of minicond to the newest version (25.5.0) instead. After that, the install of parcels 3.1.2 worked. I don't think I tried to force the version when installing parcels on the old conda version, but it is possible that I did, but without success. There was never a specific error eluding to needing to update conda, I just learned it from a google search. Sorry I can't be more specific; all the warnings were lost because I had to close the terminal window repeatedly.

Thanks,
Johanna

[VeckoTheGecko]

I see. Thanks for the explanation - we'll account for this in #2015 :)