title: Exporting / Importing trees created with python anytree 2.4.3 library
body: <p>I create a tree with anytree library. I want to be able to modify it, then export - save it to disk, and import it back with the modifications. For instance, the example tree:</p>
  
  <pre><code>udo = Node("Udo")
  marc = Node("Marc", parent=udo)
  lian = Node("Lian", parent=marc)
  dan = Node("Dan", parent=udo)
  jet = Node("Jet", parent=dan)
  jan = Node("Jan", parent=dan)
  joe = Node("Joe", parent=dan)
  
  Udo
  ├── Marc
  │   └── Lian
  └── Dan
      ├── Jet
      ├── Jan
      └── Joe
  </code></pre>
  
  <p>I can modify it, for instance cutting Dan off and adding a children to Marc </p>
  
  <pre><code>dan.parent = None 
  bonny = Node ("Bonny", parent = marc)
  
  Udo
  └── Marc
      ├── Lian
      └── Bonny
  </code></pre>
  
  <p>But when I export the tree to json and then import it back, the only node I seem to be able to reference is the root. So I can't do this kind of modification anymore because the variable names like <code>dan</code> or <code>marc</code> are not there, ie, I don't find a way to reference a node. Am I missing anything?</p>
  
  <pre><code>with open ('cajon/anytreeexample.json', 'r+', encoding = 'utf-8') as f:
      datos = importer.read(f)
  
  print (datos)
  </code></pre>
  
  <p>This means that after importing the tree what you have is just a  root node</p>
  
  <pre><code>AnyNode(name='Udo')  # Udo is the root
  </code></pre>
  
  <p>From here you can get Udo's children, and the children's children like</p>
  
  <pre><code>marc, dan = udo.children
  lian = marc.children
  jet, jan, joe = dan.children
  </code></pre>
  
  <p>But they are not working as a node</p>
  
  <pre><code>print (lian.parent)
  AttributeError: 'tuple' object has no attribute 'parent'
  </code></pre>
  
  <p>And seems you cannot attach a children to them, which is my main purpose with this structure:</p>
  
  <pre><code>sonny = AnyNode("Sonny", parent = lian)
  TypeError: __init__() got multiple values for argument 'parent'
  </code></pre>
  
  <p>So my question is, is there a way to load the json saved tree into a proper anytree structure, where you can append new nodes?</p>