[Python] Dynamic filename with TimedRotatingFileHandler

I would like to store log records for never ending process in log file with date prefix (e.g. 20250311.log).

How could I use a dynamic date for current date file, i.e.

• f"{dt.datetime.now().strftime('%Y%m%d')}.log"

Currently, I use a static name, e.g. process.log and rename the file at midnight using namer attribute of handler.

import datetime as dt
import logging
from logging.handlers import TimedRotatingFileHandler

logger = logging.getLogger("test")
handler = TimedRotatingFileHandler("process.log", when="midnight")
handler.namer = lambda _: (dt.datetime.now() - dt.timedelta(days=1)).strftime("%Y%m%d_process.log")
logger.addHandler(handler)


Disadvantage is that I need a convention for current date logs - I cannot just open a file with today's date.

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