'Returns the last non-zero term of ``f``.
Examples
>>> from sympy import Poly
>>> from sympy.abc import x, y
>>> Poly(4*x**2 + 2*x*y**2 + x*y + 3*y, x, y).ET()
(x**0*y**1, 3)'

def ET(f, order=None):

    (monom, coeff) = f.terms(order)[(-1)]
    return (Monomial(monom, f.gens), coeff)
