def METHOD_NAME(self, pol, x):
    r"""
    Return the action of ``pol`` on ``x``.
    INPUT:
    - ``pol`` -- a function ring element
    - ``x`` -- an element in the field acted upon
    OUTPUT: an element in the base codomain
    EXAMPLES::
        sage: Fq.<z2> = GF(11)
        sage: A.<T> = Fq[]
        sage: K.<z> = Fq.extension(2)
        sage: phi = DrinfeldModule(A, [z, 0, 0, 1])
        sage: action = phi.action()
        sage: P = T + 1
        sage: a = z
        sage: action(P, a)
        4*z + 2
        sage: action(0, K.random_element())
        0
        sage: action(A.random_element(), 0)
        0
    """
    if pol not in self._drinfeld_module.function_ring():
        raise TypeError('first input must be in the function ring')
    if x not in self._base:
        raise TypeError('second input must be in the field acted upon')
    return self._drinfeld_module(pol)(x)