pint-convert fails with uncertainties related error if numpy is not installed as well - document numpy dependence or give a better error message

[doronbehar]

I'm experiencing the following error when trying out the pint-convert executable:

$ pint-convert '32 m/s' 'mile/hour'
Traceback (most recent call last):
  File "/nix/store/c46r9a4x6c67dwr7mb0l6d00apb723l2-python3.11-pint-0.24/bin/.pint-convert-wrapped", line 6, in <module>
    from pint.pint_convert import main
  File "/nix/store/c46r9a4x6c67dwr7mb0l6d00apb723l2-python3.11-pint-0.24/lib/python3.11/site-packages/pint/pint_convert.py", line 106, in <module>
    (R_i, g_e, m_u, m_e, m_p, m_n) = uncertainties.correlated_values_norm(
                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'uncertainties' has no attribute 'correlated_values_norm'

My uncertainties version is 3.2.1 - upstream's latest. I also experienced this error with uncertainties 3.1.7. The uncertainties version should ideally be specified in pyproject.toml.

[andrewgsavage]

try pint-convert 32m/s mile/hour

[doronbehar]

try pint-convert 32m/s mile/hour

Same error.

[andrewgsavage]

do you have uncertainties installed?

…

On Sat, Jun 22, 2024 at 6:26 PM Doron Behar ***@***.***> wrote: try pint-convert 32m/s mile/hour Same error. — Reply to this email directly, view it on GitHub <#2016 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADEMLECFNAFVLBLJPSUJQV3ZIWXT7AVCNFSM6AAAAABJL4BVK6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCOBUGEYTMNBVHE> . You are receiving this because you commented.Message ID: ***@***.***>

[doronbehar]

do you have uncertainties installed?

Yes. I wrote that in the initial bug report, and I mentioned I tried with different versions of uncertainties. Please read thoroughly.

[andrewgsavage]

sorry I mean does it show when you load python and import uncertainties?

I got that error until I had installed uncertainties

[doronbehar]

sorry I mean does it show when you load python and import uncertainties?

I appreciate your effort to help out, but you'll need to trust me, it's not the first time I'm playing with Python packages and installations. In NixOS we don't run exactly "install" packages, but that's out of topic for this discussion. For the sake of the discussion, trust me, I have uncertainties "installed".

Note also the error I quoted in the initial bug report:

AttributeError: module 'uncertainties' has no attribute 'correlated_values_norm'

This means the uncertainties is installed - otherwise there would have been a ModuleNotFoundError instead.

I got that error until I had installed uncertainties

It would be interesting to know which uncertainties version do you have installed.

[andrewgsavage]

ahh it'll be because you don't have numpy in that env

[doronbehar]

OK That worked. Thanks! It would have been nice if this was documented or if the error message would have been better. I updated the title of the issue to reflect that.

[daspk04]

I got some issues while using pint-convert by default, but adding uncertainties package from Nixpkgs worked for me.

Nixos : 24.05
Python: 3.12
uncertainties: 3.1.7
Pint: 0.23

command without uncertainties (worked for me):

pint-convert '32 m/s' 'mile/hour' -U

In my opinion -U should be set as True by default or changed name to --with-unc. Incase one explicitly needs uncertainties, they should explicitly pass command --with-unc and install the optional dependency i.e. uncertainties.

[andrewgsavage]

yes that would be better. PRs are welcomed

[doronbehar]

In my opinion -U should be set as True by default or changed name to --with-unc. Incase one explicitly needs uncertainties, they should explicitly pass command --with-unc and install the optional dependency i.e. uncertainties.

I have a better idea: If there are no indications in the command line arguments that uncertainties should be calculated, then uncertainties shouldn't even be loaded - so there won't be such an error in case it is not even installed. A nicer message suggesting the user to install uncertainties and numpy should be printed in case the command line arguments do require it.

Specifically for you @pratyush1991 , a Nix specific PR that fixes this experience is available at NixOS/nixpkgs#320113 . Your review and 👍 will be most welcome.

[daspk04]

yes that would be better. PRs are welcomed

Thanks @andrewgsavage ! I have added it #2032