pygr/logger.py

   1 """
   2 Implements logging functionality
   3
   4 Upon import creates a module level log class (log) and
   5 the following logging functions:
   6
   7 debug, info, warn and error
   8
   9 The default formatters will print out the function the log was triggered from.
  10 """
  11
  12 import sys, logging
  13
  14 # python 2.5 the watershed release that introduced most changes since 2.1
  15
  16 PYTHON_25 = sys.version_info >= (2, 5)
  17
  18 def get_logger(name='pygr-log', stream=sys.stdout, formatter=None):
  19     """
  20     Returns a logger
  21
  22     >>> disable('INFO')
  23     >>> info('logtest, this message SHOULD NOT be visible')
  24     >>> disable()
  25     >>> info('logtest, this message should be visible')
  26     >>> disable('DEBUG')
  27     >>> debug('logtest, this message SHOULD NOT be visible')
  28     >>> info('logtest, this message should be visible')
  29     """
  30     logger = logging.getLogger(name)
  31
  32     # this is needed in case the process is
  33     # forked/multithreaded; loggers exist in a global scope
  34     # we don't want each import to duplocate this handler
  35
  36     if not logger.handlers:
  37         console = logging.StreamHandler(stream)
  38         console.setLevel(logging.DEBUG)
  39         if PYTHON_25:
  40             format = '%(levelname)s %(module)s.%(funcName)s: %(message)s'
  41         else:
  42             format = '%(levelname)s %(module)s: %(message)s'
  43
  44         formatter = formatter or logging.Formatter(format)
  45         console.setFormatter(formatter)
  46         logger.addHandler(console)
  47         logger.setLevel(logging.DEBUG)
  48     return logger
  49
  50 def disable(level=0):
  51     """
  52     Disables logging levels
  53     Levels: DEBUG, INFO, WARNING, ERROR
  54
  55     >>> disable('INFO')
  56     >>> info('logtest, this message SHOULD NOT be visible')
  57     """
  58     level = str(level)
  59     value = dict(NOTSET=0, DEBUG=10, INFO=20, WARNING=30, ERROR=40)\
  60             .get(level.upper(), 0)
  61     logging.disable(value)
  62
  63 # populate some loggers by default
  64 log = get_logger()
  65 debug, info, warn, error = log.debug, log.info, log.warn, log.error
  66
  67 def test(verbose=0):
  68     "Performs module level testing"
  69     import doctest
  70     doctest.testmod(verbose=verbose)
  71
  72 if __name__ == "__main__":
  73     test()
  74