while

tomer

1. 
   
2. fridge={"egg":"5","bread":"6","tomato":"6","juice":"3","apple":"5"}
   
3. fridge_list=[]
   
4. while i in fridge.keys()
   
5. fridge_list.append(i)
   
6. print(fridge_list)
   

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想得到fridge_list=["egg","bread","tomato","juice","apple"]

TasteOracle

1、while后面需要加“：”
2、while里的变量要做初始赋值
3、while不需要，你直接打印fridge.keys()不就是你需要的吗

tomer

回复 2# TasteOracle


    fridge.keys()结果是
dict_keys(['apple', 'tomato', 'juice', 'bread', 'egg'])
怎么还有个“dict_keys",不想要
>>> fridge={"egg":"5","bread":"6","tomato":"6","juice":"3","apple":"5"}
>>> fridge.keys()
dict_keys(['apple', 'tomato', 'juice', 'bread', 'egg'])
>>> aa=[]
>>> aa=fridge.keys()
>>> print(aa)
dict_keys(['apple', 'tomato', 'juice', 'bread', 'egg'])
>>>

tomer

回复 2# TasteOracle


    这里使用：

1. 
   
2. 
   
3. fridge={"egg":"5","bread":"6","tomato":"6","juice":"3","apple":"5"}
   
4. fridge_list=list(fridge)
   
5. print(fridge_list)
   
6. 
   

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可以得到想要的结果，但是我就想用while循环，怎么才能出这样的结果呢

whitelotus19

1. >>> fridge={"egg":"5","bread":"6","tomato":"6","juice":"3","apple":"5"}
   
2. >>> fridge
   
3. {'tomato': '6', 'juice': '3', 'egg': '5', 'apple': '5', 'bread': '6'}
   
4. >>> [x for x in fridge.keys()]
   
5. ['tomato', 'juice', 'egg', 'apple', 'bread']
   
6. >>> fridge.keys()
   
7. dict_keys(['tomato', 'juice', 'egg', 'apple', 'bread'])
   
8. >>>
   

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tomer

回复 5# whitelotus19


    如何使用while:

whitelotus19

tomer 发表于 2014-11-01 21:53
回复 5# whitelotus19

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

tomer

回复 7# whitelotus19

书上要求用while