合并字典列表时如何删除对偶

Question

我正在尝试对以下词典列表进行合并，但是我得到了重复项，如何删除重复项？

x =[{'Charles':'father','John':'son'},{'Charles':'father'}]
f =[{'Sarah':'mother','Peter':'secondson'},{'Charles':'father'}]
res = list(x+f)
print res

输出：-

[{'Charles': 'father', 'John': 'son'}, {'Charles': 'father'}, {'Sarah': 'mother', 'Peter': 'secondson'}, {'Charles': 'father'}]

预期的输出：-

[{'Charles': 'father', 'John': 'son'}, {'Charles': 'father'}, {'Sarah': 'mother', 'Peter': 'secondson'}]