How do I put together a function and a Polynomial with a division operator?

Question

Suppose I have the following function g :

import numpy as np
from numpy.polynomial import Polynomial as P

def g(x):
    return np.log(x)

And I have the following NumPy Polynomial q :

q = P([0, 1])

I want to put them together like so:

fancy = g / q
# TypeError: unsupported operand type(s) for /: 'Polynomial' and 'function'

So that I can call fancy(x) , such that it's the equivalent to saying:

g(x) / q(x)

It should be trivial to just say:

def fancy(x):
    return g(x) / q(x)

But no, I need the callable function itself, because g gets redefined at each iteration of a loop.

Answer 1

fancy = lambda x : g(x) / q(x)

Should give you what you want. lambda expressions are one way python supports creating function object on the fly. I say 'one' because you could def a function more than once, since it does pretty much the same thing assigning a lambda expression does, defines a function object and assigns it to a reference.