按层次排列列表

Question

我有一张单子

a = ["Asia/Pacific", "North America", "India,Asia/Pacific", "China, Asia/Pacific", "New Delhi, India, Asia/Pacific", "Bangalore, India,Asia/Pacific",  "Shangai, China, Asia/Pacific", "US, North America", "New York, US, North America"]

我希望它的排序方式，使所有的叶子和父节点走到一起。例如：

a = ["Asia/Pacific", "India,Asia/Pacific", "New Delhi, India, Asia/Pacific", "Bangalore, India,Asia/Pacific",  "China, Asia/Pacific", "Shangai, China, Asia/Pacific", "North America", "US, North America", "New York, US, North America"]

更清楚地说，它应该遵循一种树形结构，如-

Asia/Pacific
   India
       Bangalore
            Sarjapur Road
            MG Road
       Mumbai
             Santa Cruz
   China
       Beijing
       Shanghai

North America
   USA
   Canada
   Mexico

我怎么走？你知道吗

Answer 1

构建反映结构的键；按逗号和反转拆分：

sorted(a, key=lambda p: map(str.strip, p.split(',')[::-1]))

这将按字母顺序对最后一个组件进行排序，然后对同一地区按字母顺序对国家进行排序，等等。需要str.strip映射来删除多余的空格。你知道吗

演示：

>>> a = ["Asia/Pacific", "North America", "India,Asia/Pacific", "China, Asia/Pacific", "New Delhi, India, Asia/Pacific", "Bangalore, India,Asia/Pacific",  "Shangai, China, Asia/Pacific", "US, North America", "New York, US, North America"]
>>> sorted(a, key=lambda p: map(str.strip, p.split(',')[::-1]))
['Asia/Pacific', 'China, Asia/Pacific', 'Shangai, China, Asia/Pacific', 'India,Asia/Pacific', 'Bangalore, India,Asia/Pacific', 'New Delhi, India, Asia/Pacific', 'North America', 'US, North America', 'New York, US, North America']