def test_evaluate():
f = x**2*y*z + 2*x*y*z**3 + 3*x*y + 4*y*z
p = Poly(f, x, y, z)
assert p.evaluate({x: 7}) == Poly(f.subs({x: 7}), y, z)
assert p.evaluate({x: 7, y: 5}) == Poly(f.subs({x: 7, y: 5}), z)
assert p.evaluate({x: 7, y: 5, z: 4}) == f.subs({x: 7, y: 5, z: 4})
p = Poly(x**2 + x*y*sin(z), x, y, order='lex')
assert p.evaluate({x: 3, y: 0}) == 9
assert p.evaluate({x: 0, y: 0}) == 0
q = p.evaluate({x: 0})
assert q == Poly(0, y, order='lex')
assert q.is_zero == True
assert p.evaluate({y: 0}) == \
Poly(x**2, x, order='lex')
raises(PolynomialError, "Poly(x + y, x, y).evaluate({x: y})")
def test_evaluate():
f = x**2*y*z + 2*x*y*z**3 + 3*x*y + 4*y*z
p = Poly(f, x, y, z)
assert p.evaluate({x: 7}) == Poly(f.subs({x: 7}), y, z)
assert p.evaluate({x: 7, y: 5}) == Poly(f.subs({x: 7, y: 5}), z)
assert p.evaluate({x: 7, y: 5, z: 4}) == f.subs({x: 7, y: 5, z: 4})
p = Poly(x**2 + x*y*sin(z), x, y, order='lex')
assert p.evaluate({x: 3, y: 0}) == 9
assert p.evaluate({x: 0, y: 0}) == 0
q = p.evaluate({x: 0})
assert q == Poly(0, y, order='lex')
assert q.is_zero == True
assert p.evaluate({y: 0}) == \
Poly(x**2, x, order='lex')
raises(PolynomialError, "Poly(x + y, x, y).evaluate({x: y})")
