Конвентирование строк в файле из 3х строк в 2х строковый

#import requests
#
#
# url = 'http://some_site.kz/playlist.m3u8'
# myfile = requests.get(url)
# open('_7.m3u8', 'wb').write(myfile.content)
groupSet = set()
channels = []
urls = []
channelsDict = {}
result = []
with open('_7.m3u8', 'r', encoding='utf8') as playlist:
    for line in playlist:
        if line.find('#EXTINF:0') != -1:
            temp = line.split(',')
            channels.append(temp[1].strip())
with open('_7.m3u8', 'r', encoding='utf8') as playlist1:
    for line1 in playlist1:
        if line1.find('#EXTGRP:') != -1:
            group = line1.replace('#EXTGRP:', '').strip()
            if group != 'HD':
                group = group[0].upper() + group[1:]
            groupSet.add(group)
            name = prev_line.strip().split(',')
            urls = next(playlist1)
            channelsDict.setdefault(group, []).append(name)
            channelsDict.setdefault(group, []).append(urls)
        prev_line = line1
#channels.pop('Новости')
#channels.pop('Кино')
result.append('#EXTM3U x-tvg-url="http://epg.it999.ru/epg.xml.gz"\n')
#...
# дальше никак не могу додуматься

#channels.pop('Новости')
#channels.pop('Кино')

#import requests
#
#
# url = 'http://some_site.kz/playlist.m3u8'
# myfile = requests.get(url)
# open('_7.m3u8', 'wb').write(myfile.content)
groupSet = set()
channelsDict = {}
result = []
with open('_7.m3u8', 'r', encoding='utf8') as playlist1:
    for line1 in playlist1:
        if line1.find('#EXTGRP:') != -1:
            group = line1.replace('#EXTGRP:', '').strip()
            if group != 'HD':
                group = group[0].upper() + group[1:]
            groupSet.add(group)
            name = prev_line.strip().split(',')
            urls = next(playlist1)
            channelsDict.setdefault(group, []).append(name)
            channelsDict.setdefault(group, []).append(urls)
        prev_line = line1
#channels.pop('Новости')
#channels.pop('Кино')
result.append('#EXTM3U x-tvg-url="http://epg.it999.ru/epg.xml.gz"\n')
for grp, chnlUrl in channelsDict.items():
    result.append(f'{chnlUrl[0][0].lstrip()} group-title="{grp}" tvg-name="{chnlUrl[0][1]}",{chnlUrl[0][1]}\n{chnlUrl[1]}')
print(*result)