This chapter shall not apply to any public officer or officer of a court, who in pursuance of his duty as such officer shall conduct within the city an auction sale pursuant to any law of the state or of the United States of America, or order of a court, nor to licensed pawnbrokers or loan companies selling or offering for sale unredeemed pledges or chattels in the manner provided by law, nor to the sale of livestock by auction. (Prior code § 3-1)