Get The Elements From Nested Json With Python Using Json Lib

I want to list all the elements from 'BoxDet' with the 'BoxDet' name. The aim is to list it that way: BoxDet : ABC ... A little part of my JSON: { 'id':1, 'name':'BoxH',

Solution 1:

You need a tree-search algorithm for this:

def locateByName(e,name):
    if e.get('name',None) == name:
        return e

    for child in e.get('children',[]):
        result = locateByName(child,name)
        if result is not None:
            return result

    return None

Now you can use this recursive function to locate the element you want:

node = locateByName(output_json, 'BoxDet')
print node['name'],node['Ids']

Solution 2:

when you try to use a for loop on a dict, without any special consideration, you get only the keys out of the dict. That is:

>>> my_dict = {'foo': 'bar', 'baz':'quux'}
>>> list(my_dict)
['foo', 'baz']
>>> for x in my_dict:
... printrepr(x)    
'foo''baz'

The most usual thing to do is to use dict.iteritems() (just dict.items() in python 3)

>>> for x in my_dict.iteritems():
... printrepr(x)
('foo', 'bar')
('baz', 'quux')

Or you can fetch the value for the key yourself:

>>> for x in my_dict:
... printrepr(x), repr(my_dict[x])    
'foo''bar''baz''quux'

Solution 3:

If you want to iterate through the children of your entities you can do the following:

for children in output_json["children"]:
    #Going down to ID: 100 levelfor grandchildren in children["children"]:
        #Going down to ID: 1003 levelfor grandgrandchildren in grandchildren["children"]:
            #Going down to ID: 1019 levelif grandgrandchildren["name"] == "BoxDet":
                return"BoxDet" + " ".join(grandgrandchildren["Ids"])

Not that the data structure involved in the json module works more or less like classic dictionary where you access the value through the key:

my_dict[key] = value

Solution 4:

try it like this:

output_json = json.load(open('root.json'))
if"children"in output_json:
  children = output_json["children"]
  if"children"in children:
    children1 = children["children"]
    if"children"in children1:
      children2 = children1["children"]
      if"name"in children2:
        name = children2["name"]
      if"Ids"in children2:
        ids = children2["Ids"]
      print name, ids