Simple script to filter or filter out events of an ics file based on their name (summary) using regex

ics-filter.py

#!/usr/bin/env python3

from ics import Calendar

import argparse
import re
import sys


def main():
    arg_parser = argparse.ArgumentParser()
    arg_parser.add_argument("-i", "--input", help="Input file in ics format")
    arg_parser.add_argument(
        "-f", "--filter", help="RegEx filter events by summary/name"
    )
    arg_parser.add_argument(
        "-fo", "--filterout", help="RegEx filter out events by summary/name"
    )
    arg_parser.add_argument("-o", "--output", help="Output file in ics format")
    args = arg_parser.parse_args()

    input_file = args.input
    output_file = args.output

    if not input_file or not output_file:
        print("Please provide a path to an input and output file!")
        sys.exit(1)

    re_filter = None if args.filter is None else re.compile(args.filter, re.I)
    re_filterout = None if args.filterout is None else re.compile(args.filterout, re.I)

    if not (bool(re_filter) ^ bool(re_filterout)):
        print("You can either provide filter or filterout, not both or neither!")
        sys.exit(1)

    cal = None

    with open(input_file, "r") as f:
        cal = Calendar(f.read())

    if re_filter:
        cal.events = {
            event for event in cal.events if bool(re.search(re_filter, event.name))
        }

    if re_filterout:
        cal.events = {
            event
            for event in cal.events
            if not bool(re.search(re_filterout, event.name))
        }

    with open(output_file, "w", newline="\n") as f:
        f.writelines(cal.serialize_iter())


if __name__ == "__main__":
    main()