Question

I would like to mention that this is a homework but am not asking for help related to code.

I am having this strange problem . I am trying to implement a btree deletion and am having some recursive return problem

def delete ( tree , node , value ) :
     if node.leaf == True:
          # delete value from node 
          return tree

     elif node.leaf == False and value in node:
           # do other stuff

     else :
          delete(tree,node.Child,value)
          #recurse till you find leaf node

This is just a pseudo code as I can’t post my entire code here. The problem coming is that

when I write delete(Tree,Tree.root,value) it runs first time recurses and executes the leaf node portion but returns me a None value.

I have checked out everything and even printed stuff just above the return tree statement and it is fine with tree having some value up till there.

Can anybody tell me what am I doing wrong in this recursive function….

Thanks a lot..

Answer 1

A quick guess, fix to to:

 ...
 else:
      return delete(tree,node.Child,value) # you missed the return here
 ...

And I guess you should recurse into all children of the node, not only one (there might be more than one, right?).