Python降序字数

我正在使用这段代码来计算文本文件中单词出现的频率:

#!/usr/bin/python 
file=open("out1.txt","r+") 
wordcount={} 
for word in file.read().split(): 
    if word not in wordcount: 
        wordcount[word] = 1 
    else: 
        wordcount[word] += 1 
for k,v in wordcount.items(): 
    print k, v 

如何按频率数字的降序打印输出？