python怎样对字典排序？

Question

有一字典{"A":5,"C":4,"B":10,"D":20}怎样最快对这个字典按照value降序排列，变成{“D”:20,"B":10,"A":5,"C":4}?

Answer 1

dic={"A":5,"C":4,"B":10,"D":20}print(sorted(dic.items(),key=lambdaa:a[1],reverse=True))
                            

Answer 2

字典本身是无序的，需要先转成元组再排序如下：
a={"A":5,"C":4,"B":10,"D":20}
importoperator
#按值排序排序
b=sorted(a.items(),key=operator.itemgetter(1),reverse=True)
print(b)