Passing parameterized function handle in Python

Question

I have a general function that defines a form of an ODE that I plan to integrate using scipy.integrate.odeint, for example:

def my_ode(K, tau, y, u):
  return K*u/tau - y/tau  # dydt

I have several objects in my code that all have dynamics of the form defined in my_ode, but with unique parameters K and tau. I would love to be able to just pass a unique handle to my_ode with those parameters already set when I initialize my objects, so that when I update my objects, all I have to do is something like soln = odeint(my_ode, t, y, u) for some simulation time t.

For example, if I define a class:

class MyThing:
  def __init__(self, ode, y0):
    # I would rather not maintain K and tau in the objects, I just want the ODE with unique parameters here.
    self.ode = ode
    self.y = y0
    self.time = 0.0

  def update(self, t, u):
    # I want this to look something like:
    self.y = scipy.integrate.odeint(self.ode, t, self.y, u)

Can I do something with Lambdas when I initialize instances of MyThing to basically assign parameters K and tau at initialization and never need to pass them again? I am a bit stuck.

Answer 1

If you have:

def my_ode(K, tau, y, u):
    return K*u/tau - y/tau

you could define something like:

def make_ode_helper(k, tau): 
    return lambda (y, u): my_ode(K, tau, y, u)

and should be able to initialize MyThing with:

mt = new MyThing(make_ode_helper(k, tau), y0)

then you could call this helper with only y and u parameters:

someresult = ode_helper(y, u)