def test_zeta():
x = Symbol("x")
y = Symbol("y")
e1 = sympy.zeta(sympy.Symbol("x"))
e2 = zeta(x)
assert sympify(e1) == e2
assert e2._sympy_() == e1
e1 = sympy.zeta(sympy.Symbol("x"), sympy.Symbol("y"))
e2 = zeta(x, y)
assert sympify(e1) == e2
assert e2._sympy_() == e1
def test_zeta():
x = Symbol("x")
assert zeta(1) == zoo
assert zeta(1, x) == zoo
assert zeta(0) == Rational(-1, 2)
assert zeta(0, x) == Rational(1, 2) - x
assert zeta(1, 2) == zoo
assert zeta(1, -7) == zoo
assert zeta(2, 1) == pi**2 / 6
assert zeta(2) == pi**2 / 6
assert zeta(4) == pi**4 / 90
assert zeta(6) == pi**6 / 945
assert zeta(2, 2) == pi**2 / 6 - 1
assert zeta(4, 3) == pi**4 / 90 - Rational(17, 16)
assert zeta(6, 4) == pi**6 / 945 - Rational(47449, 46656)
assert zeta(-1) == -Rational(1, 12)
assert zeta(-2) == 0
assert zeta(-3) == Rational(1, 120)
assert zeta(-4) == 0
assert zeta(-5) == -Rational(1, 252)
assert zeta(-1, 3) == -Rational(37, 12)
assert zeta(-1, 7) == -Rational(253, 12)
assert zeta(-1, -4) == Rational(119, 12)
assert zeta(-1, -9) == Rational(539, 12)
assert zeta(-4, 3) == -17
assert zeta(-4, -8) == 8772
assert zeta(0, 1) == -Rational(1, 2)
assert zeta(0, -1) == Rational(3, 2)
assert zeta(0, 2) == -Rational(3, 2)
assert zeta(0, -2) == Rational(5, 2)