No contract, agreement or other obligation involving the expenditure of moneys shall be entered into, nor shall any ordinance, resolution or order for the expenditure of moneys be passed, adopted or issued by the Council, or be authorized by any officer of the City, unless the Director of Finance shall have first certified in writing to the Council, or to the proper officer, as the case may be, that the money required for such contract, agreement, obligation or expenditure is in the treasury to the credit of the fund from which it is to be drawn and not appropriated for any other purpose. The provisions of this section shall not be construed to prevent the making of contracts for a period extending beyond a single fiscal year when such contracts are otherwise authorized by this Charter or by general law. All moneys actually in the treasury to the credit of the fund from which they are to be drawn, and all moneys applicable to the payment of the obligation or appropriation involved that are anticipated to come into the treasury before the maturity of such contract, agreement or obligation, from taxes, assessments, license fees, or from sales of service, products or by-products of any municipal undertaking, and moneys to be derived from lawfully authorized bonds or notes, shall, for the purpose of such certificate, be deemed to be in the treasury to the credit of the appropriate fund, and shall be subject to such certification.