DAE-Scipy
This Python package is an extension of the native Python ODE solver Radau from the Scipy library.
It enables the introduction of use of a constant mass matrix \(M\) to solve differential-algebraic equations up to index 3 :
$$My' = f(t,y)$$
Extensions to variable mass matrices and equations of the form \(d_t g(y) = f(t,y)\) are in the works !