var imgHoverReplaceSrc = {
        init : function(sel) {
            this.sel = sel || "img";
            this.imgList = document.querySelectorAll(sel);
            this.work();
        },
        work : function() {
            var _this = this;
            this.imgList.forEach(function(item) {
                item.addEventListener("mouseenter", function() {
                    _this.changeSrc(item)
                });
                item.addEventListener("mouseleave", function() {
                    _this.changeSrc(item)
                });
            });
        },
        changeSrc : function(item) {
            if (item.getAttribute('data-src')) {
                var tmpSrc = item.src;
                item.src = item.getAttribute('data-src');
                item.setAttribute('data-src', tmpSrc);
            }
        }
    }
    imgHoverReplaceSrc.init("img");

<div class="sexangle_1">
                    <img alt="" src="/ehouse/img/item/tourism/yzyj.png"
                        data-src="/ehouse/img/item/tourism/yzyj2.png"> <img alt=""
                        src="/ehouse/img/item/tourism/zjwh.png"
                        data-src="/ehouse/img/item/tourism/zjwh2.png ">
                </div>