[Python-checkins] r87157 - in python/branches/py3k: Lib/logging/__init__.py Lib/test/test_logging.py Misc/NEWS
vinay.sajip
python-checkins at python.org
Fri Dec 10 12:42:57 CET 2010
Author: vinay.sajip
Date: Fri Dec 10 12:42:57 2010
New Revision: 87157
Log:
logging: added handler of last resort.
Modified:
python/branches/py3k/Lib/logging/__init__.py
python/branches/py3k/Lib/test/test_logging.py
python/branches/py3k/Misc/NEWS
Modified: python/branches/py3k/Lib/logging/__init__.py
==============================================================================
--- python/branches/py3k/Lib/logging/__init__.py (original)
+++ python/branches/py3k/Lib/logging/__init__.py Fri Dec 10 12:42:57 2010
@@ -33,7 +33,7 @@
'captureWarnings', 'critical', 'debug', 'disable', 'error',
'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass',
'info', 'log', 'makeLogRecord', 'setLoggerClass', 'warn', 'warning',
- 'getLogRecordFactory', 'setLogRecordFactory']
+ 'getLogRecordFactory', 'setLogRecordFactory', 'lastResort']
try:
import codecs
@@ -997,6 +997,26 @@
self.stream = self._open()
StreamHandler.emit(self, record)
+class _StderrHandler(StreamHandler):
+ """
+ This class is like a StreamHandler using sys.stderr, but always uses
+ whatever sys.stderr is currently set to rather than the value of
+ sys.stderr at handler construction time.
+ """
+ def __init__(self, level=NOTSET):
+ """
+ Initialize the handler.
+ """
+ Handler.__init__(self, level)
+
+ @property
+ def stream(self):
+ return sys.stderr
+
+
+_defaultLastResort = _StderrHandler(WARNING)
+lastResort = _defaultLastResort
+
#---------------------------------------------------------------------------
# Manager classes and functions
#---------------------------------------------------------------------------
@@ -1056,7 +1076,7 @@
"""
self.root = rootnode
self.disable = 0
- self.emittedNoHandlerWarning = 0
+ self.emittedNoHandlerWarning = False
self.loggerDict = {}
self.loggerClass = None
self.logRecordFactory = None
@@ -1415,10 +1435,13 @@
c = None #break out
else:
c = c.parent
- if (found == 0) and raiseExceptions and not self.manager.emittedNoHandlerWarning:
- sys.stderr.write("No handlers could be found for logger"
- " \"%s\"\n" % self.name)
- self.manager.emittedNoHandlerWarning = 1
+ if (found == 0):
+ if lastResort:
+ lastResort.handle(record)
+ elif raiseExceptions and not self.manager.emittedNoHandlerWarning:
+ sys.stderr.write("No handlers could be found for logger"
+ " \"%s\"\n" % self.name)
+ self.manager.emittedNoHandlerWarning = True
def getEffectiveLevel(self):
"""
@@ -1676,7 +1699,9 @@
def critical(msg, *args, **kwargs):
"""
- Log a message with severity 'CRITICAL' on the root logger.
+ Log a message with severity 'CRITICAL' on the root logger. If the logger
+ has no handlers, call basicConfig() to add a console handler with a
+ pre-defined format.
"""
if len(root.handlers) == 0:
basicConfig()
@@ -1686,7 +1711,9 @@
def error(msg, *args, **kwargs):
"""
- Log a message with severity 'ERROR' on the root logger.
+ Log a message with severity 'ERROR' on the root logger. If the logger has
+ no handlers, call basicConfig() to add a console handler with a pre-defined
+ format.
"""
if len(root.handlers) == 0:
basicConfig()
@@ -1694,15 +1721,18 @@
def exception(msg, *args, **kwargs):
"""
- Log a message with severity 'ERROR' on the root logger,
- with exception information.
+ Log a message with severity 'ERROR' on the root logger, with exception
+ information. If the logger has no handlers, basicConfig() is called to add
+ a console handler with a pre-defined format.
"""
kwargs['exc_info'] = True
error(msg, *args, **kwargs)
def warning(msg, *args, **kwargs):
"""
- Log a message with severity 'WARNING' on the root logger.
+ Log a message with severity 'WARNING' on the root logger. If the logger has
+ no handlers, call basicConfig() to add a console handler with a pre-defined
+ format.
"""
if len(root.handlers) == 0:
basicConfig()
@@ -1712,7 +1742,9 @@
def info(msg, *args, **kwargs):
"""
- Log a message with severity 'INFO' on the root logger.
+ Log a message with severity 'INFO' on the root logger. If the logger has
+ no handlers, call basicConfig() to add a console handler with a pre-defined
+ format.
"""
if len(root.handlers) == 0:
basicConfig()
@@ -1720,7 +1752,9 @@
def debug(msg, *args, **kwargs):
"""
- Log a message with severity 'DEBUG' on the root logger.
+ Log a message with severity 'DEBUG' on the root logger. If the logger has
+ no handlers, call basicConfig() to add a console handler with a pre-defined
+ format.
"""
if len(root.handlers) == 0:
basicConfig()
@@ -1728,7 +1762,9 @@
def log(level, msg, *args, **kwargs):
"""
- Log 'msg % args' with the integer severity 'level' on the root logger.
+ Log 'msg % args' with the integer severity 'level' on the root logger. If
+ the logger has no handlers, call basicConfig() to add a console handler
+ with a pre-defined format.
"""
if len(root.handlers) == 0:
basicConfig()
Modified: python/branches/py3k/Lib/test/test_logging.py
==============================================================================
--- python/branches/py3k/Lib/test/test_logging.py (original)
+++ python/branches/py3k/Lib/test/test_logging.py Fri Dec 10 12:42:57 2010
@@ -1927,6 +1927,40 @@
f = logging.Formatter('asctime', style='$')
self.assertFalse(f.usesTime())
+class LastResortTest(BaseTest):
+ def test_last_resort(self):
+ "Test the last resort handler"
+ root = self.root_logger
+ root.removeHandler(self.root_hdlr)
+ old_stderr = sys.stderr
+ old_lastresort = logging.lastResort
+ old_raise_exceptions = logging.raiseExceptions
+ try:
+ sys.stderr = sio = io.StringIO()
+ root.warning('This is your final chance!')
+ self.assertEqual(sio.getvalue(), 'This is your final chance!\n')
+ #No handlers and no last resort, so 'No handlers' message
+ logging.lastResort = None
+ sys.stderr = sio = io.StringIO()
+ root.warning('This is your final chance!')
+ self.assertEqual(sio.getvalue(), 'No handlers could be found for logger "root"\n')
+ # 'No handlers' message only printed once
+ sys.stderr = sio = io.StringIO()
+ root.warning('This is your final chance!')
+ self.assertEqual(sio.getvalue(), '')
+ root.manager.emittedNoHandlerWarning = False
+ #If raiseExceptions is False, no message is printed
+ logging.raiseExceptions = False
+ sys.stderr = sio = io.StringIO()
+ root.warning('This is your final chance!')
+ self.assertEqual(sio.getvalue(), '')
+ finally:
+ sys.stderr = old_stderr
+ root.addHandler(self.root_hdlr)
+ logging.lastResort = old_lastresort
+ logging.raiseExceptions = old_raise_exceptions
+
+
class BaseFileTest(BaseTest):
"Base class for handler tests that write log files"
@@ -2017,6 +2051,7 @@
FormatterTest,
LogRecordFactoryTest, ChildLoggerTest, QueueHandlerTest,
RotatingFileHandlerTest,
+ LastResortTest,
#TimedRotatingFileHandlerTest
)
Modified: python/branches/py3k/Misc/NEWS
==============================================================================
--- python/branches/py3k/Misc/NEWS (original)
+++ python/branches/py3k/Misc/NEWS Fri Dec 10 12:42:57 2010
@@ -63,6 +63,8 @@
Library
-------
+- logging: added "handler of last resort". See http://bit.ly/last-resort-handler
+
- test.support: Added TestHandler and Matcher classes for better support of
assertions about logging.
More information about the Python-checkins
mailing list