Subclassing PlainRegistry (but no access through facets)

[butlercj]

When describing how to make a custom registry, it is said that we can subclass pint's PlainRegistry (and other kinds of registry) like this:

import pint
class MyRegistry(pint.facets.NonMultiplicativeRegistry, pint.facets.PlainRegistry):
    pass

But this returns "AttributeError: module 'pint' has no attribute 'facets'."

I guess this is because pint's __init__ doesn't import the facets module. Instead, objects defined in facets are accessed through pint.registry, where from .facets import ... is used.

These objects (e.g. UnitRegistry, MeasurementRegistry, etc.) are subclasses of PlainRegistry, but PlainRegistry itself is defined in pint.facets.plain.registry, which we cannot access.

At this point I am stuck and I can't see how to subclass it. How can it be done?

Thank you!

[hgrecco]

We are revampin the subclassing experience to make it easier to use. The new version (coming out this week) should have a better roadmap!