def judge_dup(para):

try:
    if isinstance(para,dict):
        a = []
        for k in para:
               a.append(para[k])
        for i in a:
            if a.count(i) >1:
                return True
           else:
                return False
     else:
           print 'para is not a dict object'
except Except,e:
       print e         

参考文章：Python之list、dict、json等常见操作

判断字典中是否有重复值

>>> def has_duplicates(d):
        return len(d) != len(set(d.values()))
>>> print has_duplicates({'A': 1, 'B': 1, 'C': 3})
True
>>>

d = {'A': 1, 'B': 1, 'C': 3}

#不相等即有重复值
print len(d.values()) == len(set(d.values()))