Where did delta_degC go, and will it ever return?

[MichaelTiemannOSC]

I've been working with the development branch of pint to see whether more recent Measurement functionality can save me a lot of time working around np.isnan(measurement) issues. I'm now running into this:

pint.errors.UndefinedUnitError: 'delta_deg_Celsius' is not defined in the unit registry

And there's a lot of commentary about the problems of temperature measurements, generally. Any advice on how to walk on this thin ice while I can? And whether I should plan to return to the shore on which I started, or hurry up to a better landing point?

[jules-ch]

Delta for degree_Celsius is still there.

>>> from pint import UnitRegistry
>>> ureg = UnitRegistry()
>>> ureg.Quantity(1, "delta_degree_Celsius")
<Quantity(1, 'delta_degree_Celsius')>

deg_Celsius is not defined see the default_en.txt definition.

See line for aliases

pint/pint/default_en.txt

Line 200 in 9db2b29

degree_Celsius = kelvin; offset: 273.15 = °C = celsius = degC = degreeC

You can define a new alias if you want, see the documentation for that : https://pint.readthedocs.io/en/stable/defining.html

[MichaelTiemannOSC]

I found the errant text that introduced the wrong spelling of the unit. Thanks!

[MichaelTiemannOSC]

Thanks, Jules! I'm feeding off openscm-units and perhaps it's failing to get all the goodness out of the newly faceted pint world:

"""                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
This module handles initialization of pint functionality                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
"""

import uncertainties
from pint import set_application_registry
from pint_pandas import PintArray, PintType
from openscm_units import unit_registry
import re

# openscm_units doesn't make it easy to set preprocessors.  This is one way to do it.                                                                                                                                                                                                                                                                                                                                                                                                                                                 
unit_registry.preprocessors=[
     lambda s1: re.sub(r'passenger.km', 'pkm', s1),
     lambda s2: s2.replace('BoE', 'boe'),
]

PintType.ureg = unit_registry
ureg = unit_registry
set_application_registry(ureg)
Q_ = ureg.Quantity
M_ = ureg.Measurement
PA_ = PintArray

[hgrecco]

Just as a minor comment, remember that delta units are not defined in the text file, but automatically created for all non-multiplicative units.

Regarding facets, my feeling is that now behavior is more compartmentalized and easier to hack. Once that #1595 gets reviewed and approved, the parser will be also stripped out and maybe the formatter. (with the new delegates addition).

[MichaelTiemannOSC]

Yes indeed, I noticed that in the source code. I'm very excited to see the new version of Pint when it comes out!