Chat Log Searcher

#!/usr/bin/env python3

"""
Club Penguin Wiki chat log searcher.
Use username = None to match any user.
term may be either a string to find or a regular expression.
"""

__author__ = "Hey.youcp, nagi123"
__version__ = "1.0"
__date__ = "April 1, 2018"

import os
import html
import subprocess
import datetime
import re
import requests

def daterange(start, end):
    for i in range((end - start).days + 1):
        yield start + datetime.timedelta(i)

def search(username, term, date):
    response = requests.get(date.strftime("http://clubpenguin.wikia.com/wiki/Club_Penguin_Wiki:Chat/Logs/%d_%B_%Y?action=raw"))
    if not response.text:
        return None, 0
    lines, line_count = [], 0
    for line in response.iter_lines(decode_unicode=True):
        line = html.unescape(line)
        match = re.match(r"\[?.*?\]? <(.*?)>", line)
        if (username is None or match is not None and match.group(1).lower() == username.lower()) and re.search(term, line, flags=re.IGNORECASE):
                lines.append(line)
        line_count += 1
    return lines, line_count

def search_all(username, term, start, end):
    if username is None:
        print('Searching for "{}"'.format(term))
    else:
        print('Searching for messages by "{}" containing "{}"'.format(username, term))
    pages_found, total_results_count = 0, 0
    with open("output.txt", "w", encoding="utf-8") as output:
        for date in daterange(start, end):
            lines, line_count = search(username, term, date)
            if lines is None:
                print(date.strftime("%B %d, %Y logs not found."))
                continue
            results_count = 0
            for line in lines:
                if results_count == 0:
                    output.write(date.strftime("\n===%B %d, %Y===\n"))
                output.write(line + "\n")
                results_count += 1
            print(date.strftime("%B %d, %Y: {} lines, {} results.".format(line_count, results_count)))
            pages_found += 1
            total_results_count += results_count
    print("{} pages were processed and {} total results were found.".format(pages_found, total_results_count))
    return pages_found, total_results_count

def display(total_results_count):
    if total_results_count:
        if os.name == "nt":
            os.startfile("output.txt")
        elif os.name == "posix":
            subprocess.call(["xdg-open", "output.txt"])
    else:
        os.remove("output.txt")

def main():
    username = None
    term = r"\bHello\b"
    start = datetime.date(2018, 1, 1)
    end = min(datetime.date(2018, 8, 30), datetime.date.today())
    pages_found, total_results_count = search_all(username, term, start, end)
    display(total_results_count)

if __name__ == "__main__":
    main()