How to initialize the class only once and retain the overidden properties in python

Question

I am carrying out XML parsing for a list of XML files. I am using a module which overrides the XMLParser class of element tree. This is the code-

import sys
sys.modules['_elementtree'] = None
try:
    sys.modules.pop('xml.etree.ElementTree')
except KeyError:
    pass
import xml.etree.ElementTree as ET

class Parse():
    def __init__(self):
        self.xmlFiles  = [list_of_xmlFile_paths]

    def parse_xml_files(self):
        for filepath in self.xmlFiles:
            root = ET.parse(filepath, LineNumberingParser()).getroot()
            for elem in root:
                print(elem.start_line_numer, elem.end_line_number)


class LineNumberingParser(ET.XMLParser):
    def _start(self, *args, **kwargs):
        # Here we assume the default XML parser which is expat
        # and copy its element position attributes into output Elements
        self.element = super(self.__class__, self)._start(*args, **kwargs)
        self.element.start_line_number = self.parser.CurrentLineNumber
        self.element.start_column_number = self.parser.CurrentColumnNumber                
        return self.element

    def _end(self, *args, **kwargs):
        self.element = super(self.__class__, self)._end(*args, **kwargs)
        self.element.end_line_number = self.parser.CurrentLineNumber
        self.element.end_column_number = self.parser.CurrentColumnNumber                
        return self.element

The class LineNumberingParser gives me the begin line, end line of an xml node. My issue is that, for every xml file, the class is initialised.So this repetitive initialisation is not efficient. How can I do this by initialising the class only once? Can anyone please suggest.

Answer 1

I am still unsure how do you want to do that? It seems that ET.XMLParser class needs to be initialized on per-file basis....

However, should you find a way to go around that (e.g. by "re-initializing" the ET.XMLParser object's variables manually) you could keep an instance of the parser in LineNumberingParser as a class variable and initialize it only once.