假设我有一个包含以下项目的命令字典:
mydict = {'Rust': {'definition':'rusts definition'}, 'Iron': {'definition:'iron definition'}, 'Pyrite': {'definition':'pyrite definition'}}
如果我有一个数组:
myorder = ['Pyrite', 'Rust', 'Iron']
如何重新排序Ordered Dict,以使mydict中的项目基于myorder排序?
尝试这个:
mydict = {'Rust': {'definition':'rusts definition'}, 'Iron': {'definition':'iron definition'}, 'Pyrite': {'definition':'pyrite definition'}} myorder = ['Pyrite', 'Rust', 'Iron'] from collections import OrderedDict ordered = OrderedDict() for k in myorder: ordered[k] = mydict[k]
甚至更短:
ordered = OrderedDict((k, mydict[k]) for k in myorder)
使用上面的代码片段,ordered将包含与相同的键/值mydict,但它们将以所指定的相同顺序插入myorder。这是优点OrderedDict:对其进行迭代时,它将保留插入顺序。
ordered
mydict
myorder
OrderedDict
无法就地对现有字典进行排序(嗯,您 可以 提取所有键值对,消除它们,然后以正确的顺序再次添加它们,但这不是这个主意,对吗?),有必要创建一个新的…或者只是以指定的顺序遍历现有字典:
for k in myorder: x = mydict[k] # do something with x