Tensorflow logging messages do not appear

Question

I use tensorflow 1.2.0 installed with pip install.

When I run samples that include

import logging
tf.logging.set_verbosity(tf.         


        

Answer 1

There are really two logging systems in tensorflow: one in the C++ core (specifically tensorflow/core/platform/default/logging.{h,cc}) and the other in the Python bindings. The two systems are independent.

The one in the Python binding plays nicely with the standard Python logging module. The C++ logger is indepedently controlled by the TF_CPP_MIN_LOG_LEVEL environment variables mentioned in previous answers.

The following Python (that I locally called logtest.py) demonstrates the two systems' independence.

"""
Demonstrate independence of TensorFlow's two logging subsystems.
"""

import argparse
import tensorflow as tf
import logging

_logger = logging.getLogger( "tensorflow" )

parser = argparse.ArgumentParser( description="Demo TensorFlow logging" )

parser.add_argument("-v","--verbosity",
    default="",
    choices=['DEBUG','INFO','WARNING','ERROR','CRITICAL'],
    help="One of {DEBUG,INFO,WARNING,ERROR,CRITICAL}" )

args = parser.parse_args()

print( "Initial Python effective log level:", _logger.getEffectiveLevel() )

# If user provided an explicit Python level, set it.

if args.verbosity:
    _logger.setLevel( args.verbosity   )
    print( " ...new Python effective log level:", _logger.getEffectiveLevel() ) # ...and confirm the change.

_logger.debug(    "   DEBUG messages are emitted" )
_logger.info(     "    INFO messages are emitted" )
_logger.warn(     " WARNING messages are emitted" )
_logger.error(    "   ERROR messages are emitted" )
_logger.critical( "CRITICAL messages are emitted" )

with tf.Session() as s:
    pass # ...just to trigger TensorFlow into action to generate logging.

Running...

TF_CPP_MIN_LOG_LEVEL=0 python3 logtest.py -v CRITICAL

...shows that Python can't silence the core logging system, and

TF_CPP_MIN_LOG_LEVEL=5 python3 logtest.py -v DEBUG

...shows that the core system can't silence Python.