On 2023-01-03 at 21:24:20 +0000, c.bu...@posteo.jp wrote: > The main question here is why does Python deciecded to make all logs > go to stderr?
It makes sense to send all logging to one destination, and stderr is that place. > Maybe I totally misunderstood the intention of logging.info()?! Isn't > this the "usual applicaton output"? Aha. This seems to be the misconception. "Usual" in the sense of "the application is running as usual," but not in the sense of "the output the users usually see." Logging is the process where applications write details that ordinarily aren't visible to the user. Logs are for forensics, after the fact. There is an entire universe of software for managing (writing, reading, archiving, retrieving, searching, etc.) log files. At my last job, we wrote gigabytes of compressed logs every hour, and read roughly two or three out of a million entries to track down questions from our users. Users wouldn't have understood 99% of what was in the logs anyway. I also worked a lot in embedded systems, like telephone switches. Users (i.e., the people with the telephones) didn't have access to the switches, but when things went wrong, I could look at the switches' logs to get the their view of what happened. > If not, what messages should go into logging.info()? Can you name me some > examples? INFO level messages usually track "regular" happy-path progress through your application: reading config files, calculating results, writing report. Again, not meant for users (who would have their own progress meters, textual or graphical), but for tracking down problems when there are problems. For one example, the name of the config file, even if you only tell the users that you found a config file. HTH -- https://mail.python.org/mailman/listinfo/python-list
