Split an irssi IRC log file into multiple files (by date)

split_log.py

#!/usr/bin/python
#author: Bryan Bishop <kanzure@gmail.com>
#date: 2010-03-16
#updated: 2020-02-10
from datetime import datetime
strptime = datetime.strptime

logs = open("irclogs.txt", "r").read().split("\n")

LOG_OPENED = "--- Log opened "
DAY_CHANGED = "--- Day changed "

# first line: --- Log opened Thu Dec 13 13:55:28 2018
# format: %a %b %d %H:%M:%S %Y

#current = open("initial.log", "w")
current = None
for (idx, line) in enumerate(logs):
    if idx == 0 and LOG_OPENED in line and line[0:len(LOG_OPENED)] == LOG_OPENED:
        initial_date = strptime(line[len(LOG_OPENED):], "%a %b %d %H:%M:%S %Y")
        current = open(initial_date.strftime("%Y-%m-%d") + ".log", "w")

    elif DAY_CHANGED in line and line[0:len(DAY_CHANGED)] == DAY_CHANGED:
        date = line[len(DAY_CHANGED):]
        parsed_date = strptime(date, "%a %b %d %Y")

        current.close()
        current = open(parsed_date.strftime("%Y-%m-%d") + ".log", "w")

    current.write(line + "\n")

current.close()