How do you specify output log file using structlog?

Question

I feel like this should be super simple but I cannot figure out how to specify the path for the logfile when using structlog. The documentation states that you can use traditional logging alongside structlog so I tried this:

    logger = structlog.getLogger(__name__)
    logging.basicConfig(filename=logfile_path, level=logging.ERROR)
    logger.error("TEST")

The log file gets created but of course "TEST" doesn't show up inside it. It's just blank.

Answer 1

I was able to get an example working by following the docs to log to both stdout and a file.

import logging.config
import structlog

timestamper = structlog.processors.TimeStamper(fmt="iso")
logging.config.dictConfig({
        "version": 1,
        "disable_existing_loggers": False,
        "handlers": {
            "default": {
                "level": "DEBUG",
                "class": "logging.StreamHandler",
            },
            "file": {
                "level": "DEBUG",
                "class": "logging.handlers.WatchedFileHandler",
                "filename": "test.log",
            },
        },
        "loggers": {
            "": {
                "handlers": ["default", "file"],
                "level": "DEBUG",
                "propagate": True,
            },
        }
})
structlog.configure(
    processors=[
        structlog.stdlib.add_log_level,
        structlog.stdlib.PositionalArgumentsFormatter(),
        timestamper,
        structlog.processors.StackInfoRenderer(),
        structlog.processors.format_exc_info,
        structlog.stdlib.ProcessorFormatter.wrap_for_formatter,
    ],
    logger_factory=structlog.stdlib.LoggerFactory(),
    wrapper_class=structlog.stdlib.BoundLogger,
    cache_logger_on_first_use=True,
)
structlog.get_logger("test").info("hello")

If if you just wanted to log to a file you could use the snippet hynek suggested.

logging.basicConfig(filename='test.log', encoding='utf-8', level=logging.DEBUG)