Managing loggers¶
Several environment variables are used in order to adjust logger level and behaviour. It should be set before importing pyotb.
OTB_LOGGER_LEVEL: used to set the default OTB logger level.PYOTB_LOGGER_LEVEL: used to set the pyotb logger level.
If PYOTB_LOGGER_LEVEL isn't set, OTB_LOGGER_LEVEL will be used.
If none of those two variables is set, the logger level will be set to 'INFO'.
Available levels are : DEBUG, INFO, WARNING, ERROR, CRITICAL
You may also change the logger level after import (for pyotb only) using pyotb.logger.setLevel(level).
import pyotb
pyotb.logger.setLevel('DEBUG')Bonus : in some cases, you may want to silence the GDAL driver logger
(for example you will see a lot of errors when reading GML files with OGR).
One useful trick is to redirect these logs to a file. This can be done using
the variable CPL_LOG.
Log to file¶
It is possible to change the behaviour of the default pyotb logger as follow
import logging
import pyotb
# Optional : remove default stdout handler (but OTB will still print its own log)
pyotb.logger.handlers.pop()
# Add file handler
handler = logging.FileHandler("/my/log/file.log")
handler.setLevel("DEBUG")
pyotb.logger.addHandler(handler)
For more advanced configuration and to manage conflicts between several loggers,
see the logging module docs
and use the dictConfig() function to configure your own logger.
Named applications in logs¶
It is possible to change an app name in order to track it easily in the logs :
import os
os.environ['PYOTB_LOGGER_LEVEL'] = 'DEBUG'
import pyotb
bm = pyotb.BandMath(['image.tif'], exp='im1b1 * 100')
bm.name = 'CustomBandMathApp'
bm.execute()