#!/usr/bin/env python
# vim: set fileencoding=utf-8 :
# Andre Anjos <andre.anjos@idiap.ch>
# Sat 19 Oct 12:51:01 2013
"""Sets-up logging, centrally for Bob.
"""
import sys
import logging
from ._logging import reset
# get the default root logger of Bob
_logger = logging.getLogger('bob')
# by default, warning and error messages should be written to sys.stderr
_warn_err = logging.StreamHandler(sys.stderr)
_warn_err.setLevel(logging.WARNING)
_logger.addHandler(_warn_err)
# debug and info messages are written to sys.stdout
class _InfoFilter:
def filter(self, record): return record.levelno <= logging.INFO
_debug_info = logging.StreamHandler(sys.stdout)
_debug_info.setLevel(logging.DEBUG)
_debug_info.addFilter(_InfoFilter())
_logger.addHandler(_debug_info)
# this will setup divergence from C++ into python.logging correctly
reset(logging.getLogger('bob.c++'))
# this will make sure we don't fiddle with python callables after
# termination. See: http://stackoverflow.com/questions/18184209/holding-python-produced-value-in-a-c-static-boostshared-ptr
import atexit
atexit.register(reset)
del atexit
# helper functions to instantiate and set-up logging
[docs]def setup(logger_name, format="%(name)s@%(asctime)s -- %(levelname)s: %(message)s"):
"""setup(logger_name, [format]) -> logger
This function returns a logger object that is set up to perform logging using Bob loggers.
**Parameters:**
``logger_name`` : str
The name of the module to generate logs for
``format`` : str
The format of the logs, see :py:class:`logging.LogRecord` for more details.
By default, the log contains the logger name, the log time, the log level and the massage.
**Returns:**
``logger`` : :py:class:`logging.Logger`
The logger configured for logging.
The same logger can be retrieved using the :py:func:`logging.getLogger` function.
"""
# generate new logger object
logger = logging.getLogger(logger_name)
# add log the handlers if not yet done
if not logger_name.startswith("bob") and not logger.handlers:
logger.addHandler(_warn_err)
logger.addHandler(_debug_info)
# this formats the logger to print the desired information
formatter = logging.Formatter(format)
# we have to set the formatter to all handlers registered in the current logger
for handler in logger.handlers:
handler.setFormatter(formatter)
# set the same formatter for bob loggers
for handler in _logger.handlers:
handler.setFormatter(formatter)
return logger
[docs]def add_command_line_option(parser, short_option = '-v'):
"""Adds the verbosity command line option to the given parser.
The verbosity can by set to 0 (error), 1 (warning), 2 (info) or 3 (debug) by including the according number of --verbose command line arguments (e.g., ``-vv`` for info level).
**Parameters:**
``parser`` : :py:class:`argparse.ArgumentParser` or one of its derivatives
A command line parser that you want to add a verbose option to
``short_option`` : str
The short command line option that should be used for increasing the verbosity.
By default, ``'-v'`` is considered as the shortcut
"""
parser.add_argument(short_option, '--verbose', action = 'count', default = 0,
help = "Increase the verbosity level from 0 (only error messages) to 1 (warnings), 2 (log messages), 3 (debug information) by adding the --verbose option as often as desired (e.g. '-vvv' for debug).")
[docs]def set_verbosity_level(logger, level):
"""Sets the log level for the given logger.
**Parameters:**
``logger`` : :py:class:`logging.Logger` or str
The logger to generate logs for, or the name of the module to generate logs for.
``level`` : int
Possible log levels are: 0: Error; 1: Warning; 2: Info; 3: Debug.
"""
if level not in range(0,4):
raise ValueError("The verbosity level %d does not exist. Please reduce the number of '--verbose' parameters in your command line" % level)
# set up the verbosity level of the logging system
log_level = {
0: logging.ERROR,
1: logging.WARNING,
2: logging.INFO,
3: logging.DEBUG
}[level]
# set this log level to the logger with the specified name
if isinstance(logger, str):
logger = getLogger(logger)
logger.setLevel(log_level)
# set the same log level for the bob logger
_logger.setLevel(log_level)
__all__ = [_ for _ in dir() if not _.startswith('_')]