Iteratively process large wikipedia dump

Question

I want to parse a large wikipedia dump iteratively. I found a tutorial for this here: https://towardsdatascience.com/wikipedia-data-science-working-with-the-worlds-largest-encyclopedia-c08efbac5f5c

However, when I want to read in the data like this:

data_path = 'C:\\Users\\Me\\datasets\\dewiki-latest-pages-articles1.xml-p1p262468.bz2'

import xml.sax

class WikiXmlHandler(xml.sax.handler.ContentHandler):
    """Content handler for Wiki XML data using SAX"""
    def __init__(self):
        xml.sax.handler.ContentHandler.__init__(self)
        self._buffer = None
        self._values = {}
        self._current_tag = None
        self._pages = []

    def characters(self, content):
        """Characters between opening and closing tags"""
        if self._current_tag:
            self._buffer.append(content)

    def startElement(self, name, attrs):
        """Opening tag of element"""
        if name in ('title', 'text'):
            self._current_tag = name
            self._buffer = []

    def endElement(self, name):
        """Closing tag of element"""
        if name == self._current_tag:
            self._values[name] = ' '.join(self._buffer)

        if name == 'page':
            self._pages.append((self._values['title'], self._values['text']))

# Object for handling xml
handler = WikiXmlHandler()
# Parsing object
parser = xml.sax.make_parser()
parser.setContentHandler(handler)

# Iteratively process file
for line in subprocess.Popen(['bzcat'], 
                              stdin = open(data_path), 
                              stdout = subprocess.PIPE,shell=True).stdout:
    parser.feed(line)

    # Stop when 3 articles have been found
    if len(handler._pages) > 3:
        break

it seems like nothing happens. The handler._pages list is empty. This is where the parsed articles should be stored. I also added shell=True because otherwise I get the error message FileNotFoundError: [WinError 2].

I never worked with subprocesses in python so I don't know what the problem might be. I also tried to specify the data_path differently (with / and //).

Thank you in advance.