§ 7. Oath and bond of officers.

All municipal officers of the city, before entering upon the duties of their respective offices, shall be sworn in, in accordance with the laws of the Commonwealth by anyone authorized to administer oaths under the laws of the Commonwealth. If any person elected or appointed to any office in the city shall neglect to take such oath on or before the day on which he is to enter upon the discharge of the duties of his office, or shall for twenty days after the beginning of his term of office fail to give such bond as may be required of him by council, a vacancy in said office shall then exist.