Creating an adjacency matrix from XML in Python

Question

I am trying to create an adjacency matrix of t_lemma (other elements like nodetype, ord, etc. can be ignored, I am including them just for completness in case they are somehow needed) - meaning which t_lemma is a parent of which - from this XML document representing a syntactic analysis of a (czech) sentence, where t_lemma represents the neutral shape of a specific word.

Currently, I am using cElementTree library for Python but I am open to use some other if what I am asking is impossible or computation-time wisely hard to achieve using cElementTree

<t_tree id="t_tree-cs-s1-root">
    <atree.rf>a_tree-cs-s1-root</atree.rf>
    <ord>0</ord>
    <children id="t_tree-cs-s1-n107">
        <children>
            <LM id="t_tree-cs-s1-n108">
                <nodetype>complex</nodetype>
                <ord>1</ord>
                <t_lemma>muž</t_lemma>
                <functor>ACT</functor>
                <formeme>n:1</formeme>
                <is_clause_head>0</is_clause_head>
                <clause_number>1</clause_number>
                <a>
                    <lex.rf>a_tree-cs-s1-n1</lex.rf>
                </a>
                <gram>
                    <sempos>n.denot</sempos>
                    <gender>anim</gender>
                    <number>sg</number>
                    <negation>neg0</negation>
                </gram>
            </LM>
            <LM id="t_tree-cs-s1-n109">
                <nodetype>complex</nodetype>
                <ord>3</ord>
                <t_lemma>strom</t_lemma>
                <functor>PAT</functor>
                <formeme>n:4</formeme>
                <is_clause_head>0</is_clause_head>
                <clause_number>1</clause_number>
                <a>
                    <lex.rf>a_tree-cs-s1-n3</lex.rf>
                </a>
                <gram>
                    <sempos>n.denot</sempos>
                    <gender>inan</gender>
                    <number>sg</number>
                    <negation>neg0</negation>
                </gram>
            </LM>
        </children>
        <nodetype>complex</nodetype>
        <ord>2</ord>
        <t_lemma>zasadit</t_lemma>
        <functor>PRED</functor>
        <formeme>v:fin</formeme>
        <sentmod>enunc</sentmod>
        <is_clause_head>1</is_clause_head>
        <clause_number>1</clause_number>
        <a>
            <lex.rf>a_tree-cs-s1-n2</lex.rf>
        </a>
        <gram>
            <sempos>v</sempos>
            <verbmod>ind</verbmod>
            <deontmod>decl</deontmod>
            <tense>ant</tense>
            <aspect>cpl</aspect>
            <resultative>res0</resultative>
            <dispmod>disp0</dispmod>
            <iterativeness>it0</iterativeness>
            <negation>neg0</negation>
            <diathesis>act</diathesis>
        </gram>
    </children>
</t_tree>

What this XML represents is a tree of looking like this:

And what I am trying to get to is a matrix looking like this.

        muž     strom    zasadit
muž     1       0       -1

storm   0       1       -1

zasadit 1       1       1

Answer 1

I have figured out an answer that works on very big trees I have tested it on, though I had to take account of the element <ord> - denoting order of a word in a sentence - to eliminate the issue that would arise in case of sentences like: "Man and woman, walking day and night."

       walking
      /       \
   and        and
  /   \       /  \
man  woman  day  night

Only taking <t_lemma> into account would lead to unclear interpretation of (child->parent) function, ie: we would have two and s to which words: man, woman, day, night all lead like this:

element  parent
_______________
man      and
woman    and
day      and
night    and
and      walking
and      walking      

That turned the previous table into following:

element  parent
_______________
man:1    and:2
woman:3  and:2
day:5    and:6
night:7  and:6
and:2    walking:4
and:6    walking:4

So, here is the functional Python code:

parentDictionary = {}
def getchildlemma(element, parent):
    for i in element.findall("*"):
        if i.tag == "t_lemma":
            e = i.text

            for i in element.findall("*"):
                if i.tag == "ord":
                    e = e +":"+ i.text
            parentDictionary[e] = parent
            parent = e
        else:
            e = parent
    for i in element.findall("*"):
        if i.tag == "children" or i.tag == "LM":
            getchildlemma(i,parent)