def findmax(mylist):
    max = mylist[0]  # 先假定第一个元素是最大值
    maxdict = {"max": max}

    for item in mylist:
        if item > maxdict["max"]:
            maxdict["max"] = item

    return maxdict


mylist = [4, 8, 9, 3]
print(findmax(mylist))