[DerpDerpDerp]

Haskell has a very neat interface for this, in that you build a special type which remembers the dimensions of a matrix as you build them, and then return either the result or a failure.

It's very simple to build a function which doesn't have to understand the possible dimension conflicts and lift it to work on this new type, returning an either (or a maybe, if there's only one failure mode) in place of a definite value.

It's also very simple to propagate such errors forward, so they'll short circuit a computation when you have non-matching matrices used in a calculation that's multiple steps.

In Haskell, I don't have to remember to write special functions which guard against this: I write functions that operate on the matrices and add the guarding at the very end. I can ensure that all my calls use the guarding functions, because they have a different type signature.

Trying to do this same thing in Python require that I remember to always use the guarded calls, and doesn't have as clean of an interface to create the guarded functions from standard functions.