Python 链接

假设我有:

dic = {"z":"zv", "a":"av"} 
## Why doesn't the following return a sorted list of keys? 
keys = dic.keys().sort() 

我知道我可以执行以下操作并获得正确的结果:

dic = {"z":"zv", "a":"av"} 
keys = dic.keys() 
skeys = keys.sort()  ### 'skeys' will be None 

为什么第一个示例不起作用？

请您参考如下方法:

.sort 不返回列表。你可以这样做:

keys = sorted(dic.keys())