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POConvert recursive generator object to list
 

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    <p>I have been trying to implement a simple tree structure in Python. A tree begins at a single "root" node which has children, each of its children may have own children and so forth. </p> <p>Now, I want to print the names of all nodes of the tree, that is I want to convert it to a list. I sought to employ recursiveness but unfortunately yielding recursively returns a sub-tree of generator objects which I cannot convert to nodes.</p> <p>Could somebody help me and point out what I am doing wrong here please?</p> <pre><code>class Node: def __init__(self,name): self.name = name self.children = [] self.parent = None def appendChild(self,child): self.children.append(child) if child is not None: child.parent = self def listChildren(self): yield self for child in self.children: yield child.listChildren() raise StopIteration # test r = Node("root") n = Node("name") r.appendChild(n) n.appendChild(Node("name2")) n.appendChild(Node("name3")) c = Node("child") n.appendChild(c) c.appendChild(Node("child2")) c.appendChild(Node("child3")) r.appendChild(Node("name4")) r.appendChild(Node("name5")) r.appendChild(Node("name6")) for child in r.listChildren(): print child.name </code></pre> <p>Output:</p> <pre><code>Traceback (most recent call last): File "C:/Users/User/Documents/TreeNode.py", line 40, in &lt;module&gt; print child.name AttributeError: 'generator' object has no attribute 'name' </code></pre> <p>A generator is supposed to be called when it is being iterated over, but in my case every child in r.listChildren() is, in turn, a generator object. If this is a design flaw, then I would have to look for another way of generating a list of node names.</p> <p>Thank you in advance!</p>
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    1. USPavlo Dyban
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    1. COLooks like you want to use "yield from" http://www.python.org/dev/peps/pep-0380/ a new Python 3.3 feature
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      1. USMichael Mauderer
    2. COyou were a bit faster... :)
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      1. USQlaus
 

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