Can a class use an init method that would create other instances of the same class?

Question

Here is what I would like to achieve. I am trying to read a tree (let's say a folder structure). I would like to define a generic node in this tree and the initialization of this object should trigger the tree traversing like below

class node():
    def __init__(self, name, parent, children=[]):
        self.name = name
        self.parent = parent
        self.children = children

        nodes = "code to find children"

        for child in nodes:
            children.append(node(childname, self.name))

def main():
    Tree = node("root", "")

When this initial object is initialized it should contain the complete tree. This is for python. Would this work?

This should work as any other recursion, i.e. if there's a terminating condition. — millimoose, Feb 01 '16 at 18:23
Are you sure it's a Tree. Directed and Acyclic? If there's a cycle, you'll see a recursion error — Garrett R, Feb 01 '16 at 18:23
As an aside, it should be `def __init__(self, name, parent, children=[]):` — tdelaney, Feb 01 '16 at 18:29
@tdelaney: oops, that's on me. Look at the first revision, there were many more issues. — Martijn Pieters, Feb 01 '16 at 18:32

score 4 · Accepted Answer · edited May 23 '17 at 12:23

4

Yes, you can reference the class in the __init__ method, and you can use it to create more instances of the same class. Your approach works.

Do be careful with the children=[] default argument; that will create a shared list, stored once for that method. See "Least Astonishment" and the Mutable Default Argument for why that is going to trip you up and how to avoid that issue.

edited May 23 '17 at 12:23

Community

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answered Feb 01 '16 at 18:24

Martijn Pieters

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thanks a lot guys, and I am sorry for the mistakes in the initial post. I am not a programmer... :-) I am learning this art. – MiniMe Feb 01 '16 at 18:59

Can a class use an __init__ method that would create other instances of the same class?

1 Answers1

Can a class use an init method that would create other instances of the same class?