Python的字典的items(), keys(), values()

Python的字典的items(), keys(), values()都返回一个list

>>> dict = { 1 : 2, 'a' : 'b', 'hello' : 'world' }
>>> dict.values()
['b', 2, 'world']
>>> dict.keys()
['a', 1, 'hello']
>>> dict.items()
[('a', 'b'), (1, 2), ('hello', 'world')]
>>>

例如：
现在你有一家人的账本，算一下这一家子一共有多少钱？

note = {"Mom" : 14500, "Dad" : 24355, "Children" : 4560}

方法一：使用values()

note = {"Mom" : 14500, "Dad" : 24355, "Children" : 4560}
familySavings = 0
for saving in note.values():
    familySavings = familySavings + saving

print familySavings

方法二：使用items()

note = {"Mom" : 14500, "Dad" : 24355, "Children" : 4560}
familySavings = 0
for a,saving in note.items():
    familySavings = familySavings + saving

print familySavings

方法三：使用sum

note = {"Mom" : 14500, "Dad" : 24355, "Children" : 4560}
print sum(note.values())