def updateInfo(self, item, newlinks, oldlinks):
		'''爬虫爬完之后对数据库内容进行更新'''
		cur = self.conn.cursor()
		cur.execute("SELECT wid,did FROM Websites WHERE url=?", (item['url'],))
		wid, did = cur.fetchone()
		# website记录更新
		cur.execute("UPDATE Websites SET title=?,visited=1 WHERE wid=?", (item['title'], wid,))
		# 对应的domain记录中出度也需要更新
		cur.execute("UPDATE Domains SET outdegree=outdegree+? WHERE did=?", (len(item['links']), did,))

		# 对该网页中所有链接涉及的记录进行更新
		# 外部判断未出现过的链接
		for link,domain in newlinks:
			self.insertWebsite(link, domain)

		# 外部判断出现过的链接
		for link,domain in oldlinks:
			# 对对应的domain记录入度增加
			cur.execute("UPDATE Domains SET outdegree=outdegree+1 WHERE domain=?", (domain,))
		# 写入到文件
		self.conn.commit()
def test_fields(self):
        # test the offset and size attributes of Structure/Unoin fields.
        class X(Structure):
            _fields_ = [("x", c_int),
                        ("y", c_char)]

        self.assertEqual(X.x.offset, 0)
        self.assertEqual(X.x.size, sizeof(c_int))

        self.assertEqual(X.y.offset, sizeof(c_int))
        self.assertEqual(X.y.size, sizeof(c_char))

        # readonly
        self.assertRaises((TypeError, AttributeError), setattr, X.x, "offset", 92)
        self.assertRaises((TypeError, AttributeError), setattr, X.x, "size", 92)

        class X(Union):
            _fields_ = [("x", c_int),
                        ("y", c_char)]

        self.assertEqual(X.x.offset, 0)
        self.assertEqual(X.x.size, sizeof(c_int))

        self.assertEqual(X.y.offset, 0)
        self.assertEqual(X.y.size, sizeof(c_char))

        # readonly
        self.assertRaises((TypeError, AttributeError), setattr, X.x, "offset", 92)
        self.assertRaises((TypeError, AttributeError), setattr, X.x, "size", 92)

        # XXX Should we check nested data types also?
        # offset is always relative to the class...