xml_to_srt.py

import sys
from bs4 import BeautifulSoup

if len(sys.argv) < 2:
    print("Need file name!")
    sys.exit(2)

with open(sys.argv[1]) as f:
    s = f.read()

parse_time = lambda time: time.replace('.', ',')

def do_num(soup):
    return str(int(p_tag['xml:id'][3:]) + 1) + '\n'

def do_time(soup):
    begin = parse_time(p_tag['begin'])
    end = parse_time(p_tag['end'])
    return f'{begin} --> {end}\n'

def do_text(soup):
    text = ''
    for child in soup.find_all('tt:span'):
        text += (child.string + '\n')
    return text

srt = ''
soup = BeautifulSoup(s, 'lxml')

for div_tag in soup.find_all('tt:div'):
    for p_tag in div_tag.find_all('tt:p'):
        num = do_num(p_tag)
        time = do_time(p_tag)
        text = do_text(p_tag)
        srt += (num + time + text + '\n')

with open(sys.argv[1][:-4] + ".srt", 'w') as f:
    f.write(srt)