Script to convert WordPress posts to plain text files

wxr2txt.py

#!/usr/bin/env python

"""This script converts WXR file to a number of plain text files.

WXR stands for "WordPress eXtended RSS", which basically is just a
regular XML file. This script extracts entries from the WXR file into
plain text files. Output format: article name prefixed by date for
posts, article name for pages.

Usage: wxr2txt.py filename [-o output_dir]
"""

import os
import re
import sys
from xml.etree import ElementTree

NAMESPACES = {
		'content': 'http://purl.org/rss/1.0/modules/content/',
		'wp': 'http://wordpress.org/export/1.2/',
}
USAGE_STRING = "Usage: wxr2txt.py filename [-o output_dir]"


def main(argv):
	filename, output_dir = _parse_and_validate_output(argv)
	try:
		data = ElementTree.parse(filename).getroot()
	except ElementTree.ParseError:
		_error("Invalid input file format. Can not parse the input.")
	page_counter, post_counter = 0, 0
	for post in data.find('channel').findall('item'):
		post_type = post.find('wp:post_type', namespaces=NAMESPACES).text
		if post_type not in ('post', 'page'):
			continue
		content = post.find('content:encoded', namespaces=NAMESPACES).text
		date = post.find('wp:post_date', namespaces=NAMESPACES).text
		title = post.find('title').text
		date = date.split(' ')[0].replace('-', '')
		title = re.sub(r'[_]+', '_', re.sub(r'[^a-z0-9+]', '_', title.lower()))
		if post_type == 'post':
			post_filename = date + '_' + title + '.txt'
			post_counter += 1
		else:
			post_filename = title + '.txt'
			page_counter += 1
		with open(os.path.join(output_dir, post_filename), 'w') as post_file:
			post_file.write(content.encode('utf8'))
		post_counter += 1
	print "Saved {} posts and {} pages in directory '{}'.".format(
			post_counter, page_counter, output_dir)


def _parse_and_validate_output(argv):
	if len(argv) not in (2, 4):
		_error("Wrong number of arguments.")
	filename = argv[1]
	if not os.path.isfile(filename):
		_error("Input file does not exist (or not enough permissions).")
	output_dir = argv[3] if len(argv) == 4 and argv[2] == '-o' else os.getcwd()
	if not os.path.isdir(output_dir):
		_error("Output directory does not exist (or not enough permissions).")
	return filename, output_dir


def _error(text):
	print text
	print USAGE_STRING
	sys.exit(1)

if __name__ == "__main__":
	main(sys.argv)

Can verify the change suggested by @gkv-ckultzow has worked in Python 3.12, to replace 'w' with 'wb' to read:
with open(os.path.join(output_dir, post_filename), 'wb') as post_file:

Also for Python 3.12, put () around the content in each print statement as mentioned by @werowe. For example:

print("Saved {} posts and {} pages in directory '{}'.".format(
			post_counter, page_counter, output_dir))

No changes to any output text files created after executing the program, all 60 posts were captured in plain text in individual text files. Thanks.