python - XPath を使用した XML (Collada/Dae) ファイルの解析

Question

私の例を Qt C++ から Python に書き直したいと思います。

入力ファイル ("Plane.dae")

<?xml version="1.0" encoding="utf-8"?>
<COLLADA xmlns="http://www.collada.org/2005/11/COLLADASchema" version="1.4.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <asset>
    <contributor>
      <author>Blender User</author>
      <authoring_tool>Blender 2.83.3 commit date:2020-07-22, commit time:06:01, hash:353e5bd7493e</authoring_tool>
    </contributor>
    <created>2020-08-03T14:03:19</created>
    <modified>2020-08-03T14:03:19</modified>
    <unit name="meter" meter="1"/>
    <up_axis>Z_UP</up_axis>
  </asset>
  <library_effects>
    <effect id="PlaneMaterial-effect">
      <profile_COMMON>
        <technique sid="common">
          <lambert>
            <emission>
              <color sid="emission">0 0 0 1</color>
            </emission>
            <diffuse>
              <color sid="diffuse">0.01664001 0.8000001 0.01191879 1</color>
            </diffuse>
            <reflectivity>
              <float sid="specular">0.5</float>
            </reflectivity>
          </lambert>
        </technique>
      </profile_COMMON>
    </effect>
  </library_effects>
  <library_images/>
  <library_materials>
    <material id="PlaneMaterial-material" name="PlaneMaterial">
      <instance_effect url="#PlaneMaterial-effect"/>
    </material>
  </library_materials>
  <library_geometries>
    <geometry id="Plane-mesh" name="Plane">
      <mesh>
        <source id="Plane-mesh-positions">
          <float_array id="Plane-mesh-positions-array" count="12">-1 -1 0 1 -1 0 -1 1 0 1 1 0</float_array>
          <technique_common>
            <accessor source="#Plane-mesh-positions-array" count="4" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Plane-mesh-normals">
          <float_array id="Plane-mesh-normals-array" count="3">0 0 1</float_array>
          <technique_common>
            <accessor source="#Plane-mesh-normals-array" count="1" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Plane-mesh-map-0">
          <float_array id="Plane-mesh-map-0-array" count="12">1 0 0 1 0 0 1 0 1 1 0 1</float_array>
          <technique_common>
            <accessor source="#Plane-mesh-map-0-array" count="6" stride="2">
              <param name="S" type="float"/>
              <param name="T" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <vertices id="Plane-mesh-vertices">
          <input semantic="POSITION" source="#Plane-mesh-positions"/>
        </vertices>
        <triangles material="PlaneMaterial-material" count="2">
          <input semantic="VERTEX" source="#Plane-mesh-vertices" offset="0"/>
          <input semantic="NORMAL" source="#Plane-mesh-normals" offset="1"/>
          <input semantic="TEXCOORD" source="#Plane-mesh-map-0" offset="2" set="0"/>
          <p>1 0 0 2 0 1 0 0 2 1 0 3 3 0 4 2 0 5</p>
        </triangles>
      </mesh>
    </geometry>
  </library_geometries>
  <library_visual_scenes>
    <visual_scene id="Scene" name="Scene">
      <node id="Plane" name="Plane" type="NODE">
        <matrix sid="transform">1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1</matrix>
        <instance_geometry url="#Plane-mesh" name="Plane">
          <bind_material>
            <technique_common>
              <instance_material symbol="PlaneMaterial-material" target="#PlaneMaterial-material">
                <bind_vertex_input semantic="UVMap" input_semantic="TEXCOORD" input_set="0"/>
              </instance_material>
            </technique_common>
          </bind_material>
        </instance_geometry>
      </node>
    </visual_scene>
  </library_visual_scenes>
  <scene>
    <instance_visual_scene url="#Scene"/>
  </scene>
</COLLADA>

Qt C++:

    QString planePath = ":/Models/Plane.dae";
    QFile f(planePath);
    if (!f.open(QIODevice::ReadOnly))
    {
        std::cerr << "Failed to load the file: " <<
                     planePath.toStdString() << std::endl;
        return;
    }
 
    QXmlQuery query;
    query.bindVariable("myFile", &f);
//    query.setQuery("doc($myFile)//*[local-name() = 'p']/text()"); // it works too but it is XPath 1.0
    query.setQuery("doc($myFile)//*:p/text()");
 
    QString result;
    query.evaluateTo(&result);
    qDebug() << result;
    f.close();

Python で書き直そうとしましたが、私の例は次の行でフリーズしています。

        query.setQuery("doc($myFile)//*:p/text()")
        # query.setQuery("doc($myFile)//*[local-name() = 'p']/text()")

main.py

import sys
from PySide2.QtCore import QFile, QIODevice
from PySide2.QtXmlPatterns import QXmlQuery, QXmlResultItems
from PySide2.QtWidgets import (QApplication,
    QTextEdit, QWidget)

class Window(QWidget):

    def __init__(self):
        super().__init__()
        self.resize(250, 250)
        output = QTextEdit("", self)
        planePath = "./Plane.dae"
        f = QFile(planePath)
        if not f.open(QIODevice.ReadOnly):
            print("Falied to load the file:", planePath)
        query = QXmlQuery()
        query.bindVariable("myFile", f)
        query.setQuery("doc($myFile)//*:p/text()")
        # query.setQuery("doc($myFile)//*[local-name() = 'p']/text()")
        result = QXmlResultItems()
        query.evaluateTo(result)
        output.setText("Hello")

def main():
    app = QApplication(sys.argv)
    w = Window()
    w.show()
    sys.exit(app.exec_())

if __name__ == "__main__":
    main()