def __init__(self):
		'''创建表'''
		self.conn = sqlite3.connect("./items.db")
		if VERBOSE:
			print 'Database connection OPEN.'
		# Domain 表
		self.conn.execute(CTABLE_DOMAIN)
		# Website 表
		self.conn.execute(CTABLE_WEBSITE)
		# Rule 表 
		self.conn.execute(CTABLE_RULESETS)

		self.conn.commit()
		if VERBOSE:
			cur = self.conn.cursor()
			print 'Tables:',cur.execute("SELECT name FROM sqlite_master WHERE type = 'table'").fetchall()
def __getitem__(self, index):
        """Return example at given index.

        Args:
            index(int): The index of the example to retrieve

        Returns:
            tuple: A 4-tuple with ``(img1, img2, flow, valid_flow_mask)`` where ``valid_flow_mask``
            is a numpy boolean mask of shape (H, W)
            indicating which flow values are valid. The flow is a numpy array of
            shape (2, H, W) and the images are PIL images. ``flow`` and ``valid_flow_mask`` are None if
            ``split="test"``.
        """
        return super().__getitem__(index)