How to redirect abseil logging messages to stout instead of stderr?

Question

I am using python 3.7.6. and abseil module for logging messages with absl-py 0.9.0. I am using this piece of code for my tests.

from absl import logging
from absl import app

def main(argv):

    #logging.set_stderrthreshold(logging.ERROR)
    #logging._warn_preinit_stderr = False
    logging.set_verbosity(logging.DEBUG)

    print(' 0 -----')
    logging.debug(' 1 logging-debug-test')
    logging.info(' 2 logging-info-test')
    logging.warning(' 3 logging-warning-test')
    logging.error('4 logging-error-test')
    print(' 5 -----')

if __name__ == '__main__':
    app.run(main)

When testing it in a Jupyter notebook, it is clear from the color code of the background that abseil messages are in the stderr stream.

Same things when executing the python code in a shell:
I tried few things with different values like:

logging.set_stderrthreshold(logging.DEBUG)
logging._warn_preinit_stderr = True

but I still see 100% the same output.

• How can I redirect output abseil logging messages to stdout instead of stderr ?
• Is it expected to have the logging output messages redirect to stderr and not stdout? I am probably missing something with the logging logic and I want to better understand it.

Answer 1

I was told that this is the standard behavior and what Python's standard logging module does. In my case adding the following line redirect the logging messages to stdout:

logging.get_absl_handler().python_handler.stream = sys.stdout

Now in my Jupyter notebook it looks like that:

Answer 2

This did NOT work for me for some reason:

from absl import logging
import sys

logging.get_absl_handler().python_handler.stream = sys.stdout

But this did:

import logging
import sys

logging.basicConfig(stream=sys.stdout)