Trees

[Alex Le Dain]

Is there a generic "tree" module that can enable me to sort and use
trees (and nodes). Basically having methods such as .AddNode(),
..GetAllChildren(), .FindNode() etc.

Is this handled natively with any of the core modules?

cheers, Alex.

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[Harlin Seritt]

Would this be for a GUI toolkit or maybe using a standard class scheme?

 

[Fuzzyman]

Is there a generic "tree" module that can enable me to sort and use
trees (and nodes). Basically having methods such as .AddNode(),
.GetAllChildren(), .FindNode() etc.

Is this handled natively with any of the core modules?

cheers, Alex.

--
Poseidon Scientific Instruments Pty Ltd
1/95 Queen Victoria St
FREMANTLE WA, AUSTRALIA

Ph: +61 8 9430 6639 Fx: +61 8 9335 4650
Website: www.psi.com.au

PSI, an ISO-9001 Company

CONFIDENTIALITY: The contents of this email (and any attachments) are

confidential and may contain proprietary and/or copyright material of

Poseidon Scientific Instruments Pty Ltd (PSI) or third parties. You may
only reproduce or distribute the material if you are expressly
authorised to do so. If you are not the intended recipient, any use,
disclosure or copying of this email (and any attachments) is
unauthorised. If you have received this email in error, please
immediately delete it and any copies of it from your system and notify
PSI by return email to sender or by telephone on +61 (08) 9430 6639.

DISCLAIMER: You may only rely on electronically transmitted documents when:
(a) those documents are confirmed by original documents signed by an
authorised employee of PSI; and/or
(b) the document has been confirmed and checked against a hard copy
of that document provided by PSI.

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Long sig !!

Try elemtree by the F-bot....

Regards,

Fuzzy
http://www.voidspace.org.uk/python/index.shtml

 

[Diez B. Roggisch]

Is there a generic "tree" module that can enable me to sort and use
trees (and nodes). Basically having methods such as .AddNode(),
.GetAllChildren(), .FindNode() etc.

No. Usually, one uses the built-in python datastructures for this. E.g.

('root', [('child1', None), ('child2', None)])

Or writing a Node-class is also so straightforward that few care about them
being part of the core:

class Node(object):
def __init__(self, payload, childs=None):
self.payload = payload
self.childs = childs

def depth_first(self):
if self.childs:
for child in self.childs:
for node in child.depth_first():
yield node
yield self.payload



tree = Node('root', [Node('child1'), Node('child2')])

for n in tree.depth_first():
print n

 

[Nick Coghlan]

Or writing a Node-class is also so straightforward that few care about them
being part of the core:

Writing a *simple* node class is easy, but a full-featured one that supports
things like comparison and easy iteration is a bit more work. So various people
write partial implementations with only the features they need, and they all end
up being incompatible. So beyond being able to use it, the other thing is that
having an implementation in the standard library acts as a de facto interface
standard, making it easier to write common code to operate on tree structures.

All it would take to make it happen is a PEP, an implementation and a champion
with some persuasive ability

Cheers,
Nick.

 

[Eddie Corns]

Is there a generic "tree" module that can enable me to sort and use
trees (and nodes). Basically having methods such as .AddNode(),
.GetAllChildren(), .FindNode() etc.

http://newcenturycomputers.net/projects/rbtree.html

might do most of what you want.

Eddie

 

[Diez B. Roggisch]

Writing a *simple* node class is easy, but a full-featured one that

supports things like comparison and easy iteration is a bit more work. So
various people write partial implementations with only the features they
need, and they all end up being incompatible. So beyond being able to use
it, the other thing is that having an implementation in the standard
library acts as a de facto interface standard, making it easier to write
common code to operate on tree structures.

Hm. I disagree on that. Some things make only sense for binary trees, others
need explicit uplinking to the parent node and so on. Some want accessor
methods, others have certain operator overloadings used for a specific
functionality. So in the end, it either becomes a monstrosity or is again
not usable. But that's only my HO.

All it would take to make it happen is a PEP, an implementation and a
champion with some persuasive ability

Go wild