关于dict.values（）的结果

Question

当我尝试返回list(dict.values())时，我发现了一些非常奇怪的东西。

 class Solution:
    def groupAnagrams(self, strs):  
        dict = {}
        for i in strs:
            key = ''.join(set(i))
            if key in dict.keys():
                dict[key].append(i)
            else:
                dict.update({key:[i]})
        return list(dict.values()) 
    #The input could be ["eat","tea","tan","ate","nat","bat"]
    #And it's supposed to get the result: [["bat"],["nat","tan"],["ate","eat","tea"]]

问题是，当我打印list(dict.values())时，结果与正确答案相同。但是当我做return list(dict.values())时，每次结果都不同。它可能是[["nat"],["tan"],["eat","tea","ate"],["bat"]]，或[['eat'], ['tea'], ['tan'], ['ate'], ['nat'], ['bat']]等等。我对此为何发生了如此困惑。