Standard Library Logging

Logfire can act as a sink for standard library logging by emitting a Logfire log for every standard library log record.

Using basicConfig()Using dictConfig()

main.py

from logging import basicConfig, getLogger

import logfire

logfire.configure()
basicConfig(handlers=[logfire.LogfireLoggingHandler()])

logger = getLogger(__name__)

logger.error("Hello %s!", "Fred")
# 10:05:06.855 Hello Fred!

main.py

from logging.config import dictConfig

import logfire

logfire.configure()
dictConfig({
    'version': 1,
    'handlers': {
        'logfire': {
            'class': 'logfire.LogfireLoggingHandler',
        },
    },
    'root': {
        'handlers': ['logfire'],
    },
})

logger = getLogger(__name__)

logger.error("Hello %s!", "Fred")
# 10:05:06.855 Hello Fred!

The LogfireLoggingHandler will emit log records to the Logfire instance, unless instrumentation is suppressed, in which case a fallback handler will be used (defaults to StreamHandler, writing to sys.stderr).

Oh no! Too many logs from...

A common issue with logging is that it can be too verbose... Right?

Don't worry! We are here to help you.

In those cases, you can set the log level to a higher value to suppress logs that are less important. Let's see an example with the apscheduler logger:

main.py

import logging

logger = logging.getLogger("apscheduler")
logger.setLevel(logging.WARNING)

In this example, we set the log level of the apscheduler logger to WARNING, which means that only logs with a level of WARNING or higher will be emitted.

Disabling urllib3 debug logs

As instrumentation is suppressed when sending log data to Logfire, unexpected DEBUG logs can appear in the console (through the use of the fallback handler), emitted when performing the API request to send logs.

To disable such logs, a filter can be used:

Using basicConfig()Using dictConfig()

main.py

import logging
from logging import DEBUG, basicConfig, getLogger

import logfire

logfire.configure()
logfire_handler = logfire.LogfireLoggingHandler()

urllib3_filter = logging.Filter('urllib3')
# Disable urllib3 debug logs on the fallback handler
# (by default, writing to `sys.stderr`):
logfire_handler.fallback.addFilter(lambda record: not urllib3_filter.filter(record))

basicConfig(handlers=[logfire_handler], level=DEBUG)

main.py

import logging
from logging.config import dictConfig

import logfire

logfire.configure()

fallback = logging.StreamHandler()

urllib3_filter = logging.Filter('urllib3')
# Disable urllib3 debug logs on the fallback handler
# (by default, writing to `sys.stderr`):
fallback.addFilter(lambda record: not urllib3_filter.filter(record))

dictConfig({
    'version': 1,
    'disable_existing_loggers': False,
    'handlers': {
        'logfire': {
            'class': 'logfire.LogfireLoggingHandler',
            'level': 'DEBUG',
            'fallback': fallback,
        },
    },
    'root': {
        'handlers': ['logfire'],
        'level': 'DEBUG',
    },
})