Trillian Log Parser

import re
import urllib.parse
from datetime import datetime
import os
import html

if not os.path.exists("OUTPUT"):
    os.mkdir("OUTPUT")
else:
    for root, dirs, files in os.walk("OUTPUT"):
        for file in files:
            os.remove(root+"\\"+file)

users = {}
myname = input("Enter your own nickname: ")

for root, dirs, files in os.walk("_CLOUD"):
    for filename in files:
        if filename.endswith(".xml"):
            username = re.search(r'(.*?).xml',filename).group(1)
            users[username] = None

for user in users:
    if users[user] == None:
        alias = input("Enter an alias for \""+user+"\": ")
        if alias == "":
            defaultname = re.search(r'.*?-(.*)',user).group(1)
            print("Using default "+defaultname)
            users[user] = defaultname
        else:
            users[user] = alias

for user in users:
    print("Parsing logs for "+user+" ("+users[user]+")...")
    posts = {}
    protocol = re.search(r'(.*?)-.*', user).group(1).lower()
    if not os.path.exists("OUTPUT\\"+protocol):
        os.mkdir("OUTPUT\\"+protocol)
    for root, dirs, files in os.walk("_CLOUD"):
        for filename in files:
            if filename.endswith(".xml"):
                if re.match(user+'.xml', filename) is not None:
                    # print("OK, reading "+root+"\\"+filename)
                    with open(root+"\\"+filename) as file:
                        filelines = file.readlines()
                        for line in filelines:
                            if line.startswith("<message"):
                                try:
                                    time = re.search(r'time=\"(.+?)\"', line).group(1)
                                    type = re.search(r'type=\"(.+?)\"', line).group(1)
                                    text = re.search(r'text=\"(%20)?(.+?)\"', line).group(2)
                                except:
                                    continue
                                text = urllib.parse.unquote(text)
                                text = html.unescape(text)
                                text = re.sub(r'</?a(.*?)>', '', text)
                                text = re.sub(r'</?b(.*?)>', '**', text)
                                text = re.sub(r'</?i(.*?)>', '_', text)

                                timetext = datetime.utcfromtimestamp(int(time)/1000).strftime('%Y-%m-%d %H:%M:%S')
                                if type.startswith("incoming"):
                                    name = users[user]
                                else:
                                    name = myname
                                if text.startswith("/me"):
                                    posts[time] = "["+timetext+"] "+name+" "+text[4:]
                                else:
                                    posts[time] = "["+timetext+"] "+name+": "+text

    outputfile = open("OUTPUT\\"+protocol+"\\"+users[user]+".txt", "a", encoding="utf-8")
    for post in posts:
        # print("writing "+post)
        outputfile.write(posts[post]+"\n")
    outputfile.close()