log2csv.py

from datetime import datetime
import fileinput, re

MESSAGE_REGEX = re.compile(r'(^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}.\d{3}) .+ - ((New height|Imported|Opening import).+)$')

first_ts = 0

def process(line):
    global first_ts
    result = MESSAGE_REGEX.match(line)
    if result:
        message_ts = int(datetime.fromisoformat(result[1].replace(',', '.')).timestamp() * 1000)
        if first_ts == 0:
            first_ts = message_ts
        else:
            offset = message_ts - first_ts
            message = result[2].replace('New height: ', '')
            print(f'{offset},{message}')

for line in fileinput.input():
    process(line)