如何将这个基本列表变成一个结构化的列表？

Question

I have a fairly basic list as the following :

listOne = [parentOneObject,childOne,childTwo,childThree,parentTwoObject,childOne,childTwo...]

Sementically, this list contains parents and their child next to them, each iteml is this list is an object (An HTML Element, in reality, but this is not a problem)

Turned into a hierarchy, we get this :

-ParentOne
  -Child1
  -Child2
  -Child3
-ParentTwo
  -Child1
  -Child2

And so on ...

To distinguish parents, I check their class attribute if it contains : level-1 . Other childs have "level-i" in their class attribute, where i is an integer bigger then one .

I can't find a way to turn that list into a more structured list of dict like this:

listTwo = [{
            'parent' : parentOne,
            'children': [childOne,childTwo,childThree]
            },
            {'parent':parentTwo,
             'children': [childOne,childTwo,childThree]
            }]

I want to turn the first basic list into a list of dictionaries of parnet and children objects using the logic explained previously .

I know that I should have at least a minimum code, but for this problem I'm totally stuck, the only code I have for this is :

for item in listOne:
   #Do something to turn list one into a structured list
   pass

As you can see nothing useful, I'd love to get some help on this, doesn't have to be python, because I'm stuck at the logic level, even pseudocode is fine .

Answer 1

You need to have a way to distinguish parents from children. Then all you have to do is test for that in a loop:

listTwo = []
entry = None
for element in listOne:
    if isparent(element):  # put your test here
        entry = {'parent': element, 'children': []}
        listTwo.append(entry)
    else:  # it's a child, append to last parent
        entry['children'].append(element)

So if you can distinguish your HTML elements by a HTML class, then just test for that:

if 'level-1' in element.get('class', []):  # it's a parent

Note that if the first element in listOne is not a parent element, the entry['children'] expression will fail as entry is still set to None at that stage. This is deliberate, you'd want to know if you had an error like that.