Working with units

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astropy also has a very powerful units and quantities package which took much of its original inspiration from Pint. Actually, lately they've been converging more and more again on shared functionality (thanks in part to recent updates to Numpy making propagation of units easier)--I wonder if one day it will be possible for them to converge, rather than maintaining separate projects. Though astropy.units does have some more advanced functionality specific to the astronomy community (though also useful for most any science).

Ok, so I'm doing fine with pint with one exception: When I define a symbolic expression and then try to evaluate that expression using variables that have units. For example, I define a symbolic expression:

Vres(Vref,RES)=2*Vref/2^RES

And I try to evaluate it using a pint variable (with units I defined):

Vres(5*u.V, 20)

I get a type error:

TypeError: no canonical coercion from <class 'pint.quantity.build_quantity_class.<locals>.Quantity'> to Callable function ring with arguments (Vref, RES)

I guess this makes sense because how would the symbolic expression class know what to do with a pint type variable? Any ideas?