Source code for bob.core.log

#!/usr/bin/env python
# vim: set fileencoding=utf-8 :
# Andre Anjos <>
# 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)

# 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)

# this will setup divergence from C++ into python.logging correctly

# this will make sure we don't fiddle with python callables after
# termination. See:
import atexit
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('_')]