def robotsrulesetOfDomain(self, domain):
		'''检查domain是否在数据库中,
			否 --> (False, None)
			是 --> (True, 数据库中存储的robots.txt内容)
		'''
		exist = False
		cur = self.conn.cursor()
		# 是否存在
		cur.execute("SELECT 1 FROM Domains WHERE domain=?", (domain,))
		if cur.fetchone() :
			exist = True
		# 存在的话,结果是什么
		cur.execute("SELECT rules FROM Domains,Rulesets "
			"WHERE domain=? AND Domains.did=Rulesets.did"
			,(domain,) )
		ruleset = cur.fetchone()
		return (exist, ruleset)
def test_fresnel_coefficients():
    assert all(ae(i, j, 5) for i, j in zip(
        fresnel_coefficients(0.5, 1, 1.33),
        [0.11163, -0.17138, 0.83581, 0.82862]))
    assert all(ae(i, j, 5) for i, j in zip(
        fresnel_coefficients(0.5, 1.33, 1),
        [-0.07726, 0.20482, 1.22724, 1.20482]))
    m1 = Medium('m1')
    m2 = Medium('m2', n=2)
    assert all(ae(i, j, 5) for i, j in zip(
        fresnel_coefficients(0.3, m1, m2),
        [0.31784, -0.34865, 0.65892, 0.65135]))
    ans = [[-0.23563, -0.97184], [0.81648, -0.57738]]
    got = fresnel_coefficients(0.6, m2, m1)
    for i, j in zip(got, ans):
        for a, b in zip(i.as_real_imag(), j):
            assert ae(a, b, 5)