while循环创建列表
有一个字典fridge={"egg":8,"mushroom":20,"pepper":3,"cheese":2,"tomato":4,"milk":13}
使用while创建一个列表fridge_list,使fridge_list包含fridge的键值
我很好奇为什么这个问题一定要用while来做?for循环不是挺简单的吗 回复 2# whitelotus19
为什么学习使用while,书上要求的 fridge={"egg":8,"mushroom":20,"pepper":3,"cheese":2,"tomato":4,"milk":13}
fridge_list = {}
n = iter(fridge.iterkeys())
m = n.next()
try:
while m:
fridge_list = fridge
m = n.next()
except StopIteration:
pass 本帖最后由 ssfjhh 于 2014-11-05 14:52 编辑
In : fridge={"egg":8,"mushroom":20,"pepper":3,"cheese":2,"tomato":4,"milk":13}
In : fridge_list = list(fridge.keys())
In : fridge_list
Out: ['cheese', 'tomato', 'milk', 'mushroom', 'pepper', 'egg']
In : 这是哪本书给的例子,也太差了。 回复 5# ssfjhh
fridge_list = list(fridge.keys()) // 这个list 是多余的吧
我很好奇为什么这个 keys 这么这简单 ~
回复 6# reyleon
回复 6# reyleon |keys(...)
| D.keys() -> a set-like object providing a view on D's keys看看这条帮助,你就知道list不是多余的。 回复 8# ssfjhh
好吧,你的跟我的不同 |keys(...)
| D.keys() -> list of D's keys >>> fridge={"egg":8,"mushroom":20,"pepper":3,"cheese":2,"tomato":4,"milk":13}
>>> type(fridge.keys())
<type 'list'>
版本2.7.5
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