Multiple instances and wrong parental links

[DevPlayer]

Mere are my ramblings of a novice (bad) Hobbyst programmer.

You mentioned that your having a hard time coming up with a solution
to your complex problem. Complex means you are doing lots of different
things to different things all over the place where timing is an
issue.

First it seems you are trying to simplify your problem by creating a
generic class you might call Element which is held in an ElementList
class. Right?

Or is it you would like you to create a new class for each unique
element? If this is the case it would be because each unique element -
behaves- differently. Is this the case? Or do all XML elements
basically behave the same? If they behave the same you're confusing
your design. A class  represents a unique behavior. Remember instances
can have unique attributes like "code" or "title". But I'm digressing.

For example in your other discussion you posted at:
https://groups.google.com/forum/#!topic/comp.lang.python/K9PinAbuCJk/discussion
you say:

So, an element like:

<market code="WotF">
<title>Writers of the Future</title>
</market>

Or is the element structure?:

<some_classname code="some_value">
<title>"some value"</title>
</some_classname>

Or is it like this?

<some_classname some_tokenname="value">
<sub_element>value</subelement>
</some_classname>

Or like this?

<some_classname some_tokenname="value">
<sub_element>value</subelement>
<sub_element>value</subelement>
...
</some_classname>

Or this, typical XML?

<some_classname some_tokenname="value">
    <sub_element>value</subelement>
    <sub_element>value</subelement>
    ...
    <some_classname some_tokenname="value">
        <sub_element>value</subelement>
        <sub_element>value</subelement>
        ...
    </some_classname>
</some_classname>


And is <sub_element> nested or only one "sub" deep?

Ask yourself why do you need to have a different class for each unique
element type? Or in other words, why do you need a new class for each
XML tag pair?

If your elements are nested to some unknown depth, perhaps broaden
your idea of your ElementList into an ElementTree.

Take a look at the section "Basic Usage" midway down at url:
http://effbot.org/zone/element-index.htm


Or change you Market Class stucture(in your other discussion) to make
it more dimensional by adding a tag attribute which would
mark it as if it were a certain "class".

class ElementNode(objec):
    def__init__(self, parent, elem)
        self.parent = parent	# another elementNode object or None
        self.elem = elem     # entire text block or just do offsets
(i.e. file line numbers)
        self.tag = self.get_tag(elem)       # market  tag==class
        self.token = self.get_token(self)     # "code" or whatever if
variable
        self.sub_elems= self.get_subs(elem) # recursive ElementNodes;
return a list or dict

        self.root = self.get_root(parent)   # optional but handy
            # I like to use the root as the XML source; sometimes an
XML file
        self.next = None   # because I love double link lists
            # probably useful for that ObjectListView wxPython widget


If in your case each Element does behave differently (ie has unique
methods) then perhaps you should be looking at some other solution.
Perhaps class factories or meta classes. I can't help you there.