D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
lib64
/
python2.7
/
logging
/
Filename :
__init__.py
back
Copy
# Copyright 2001-2014 by Vinay Sajip. All Rights Reserved. # # Permission to use, copy, modify, and distribute this software and its # documentation for any purpose and without fee is hereby granted, # provided that the above copyright notice appear in all copies and that # both that copyright notice and this permission notice appear in # supporting documentation, and that the name of Vinay Sajip # not be used in advertising or publicity pertaining to distribution # of the software without specific, written prior permission. # VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING # ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL # VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR # ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER # IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. """ Logging package for Python. Based on PEP 282 and comments thereto in comp.lang.python. Copyright (C) 2001-2014 Vinay Sajip. All Rights Reserved. To use, simply 'import logging' and log away! """ import sys, os, time, cStringIO, traceback, warnings, weakref, collections __all__ = ['BASIC_FORMAT', 'BufferingFormatter', 'CRITICAL', 'DEBUG', 'ERROR', 'FATAL', 'FileHandler', 'Filter', 'Formatter', 'Handler', 'INFO', 'LogRecord', 'Logger', 'LoggerAdapter', 'NOTSET', 'NullHandler', 'StreamHandler', 'WARN', 'WARNING', 'addLevelName', 'basicConfig', 'captureWarnings', 'critical', 'debug', 'disable', 'error', 'exception', 'fatal', 'getLevelName', 'getLogger', 'getLoggerClass', 'info', 'log', 'makeLogRecord', 'setLoggerClass', 'warn', 'warning'] try: import codecs except ImportError: codecs = None try: import thread import threading except ImportError: thread = None __author__ = "Vinay Sajip <vinay_sajip@red-dove.com>" __status__ = "production" # Note: the attributes below are no longer maintained. __version__ = "0.5.1.2" __date__ = "07 February 2010" #--------------------------------------------------------------------------- # Miscellaneous module data #--------------------------------------------------------------------------- try: unicode _unicode = True except NameError: _unicode = False # next bit filched from 1.5.2's inspect.py def currentframe(): """Return the frame object for the caller's stack frame.""" try: raise Exception except: return sys.exc_info()[2].tb_frame.f_back if hasattr(sys, '_getframe'): currentframe = lambda: sys._getframe(3) # done filching # # _srcfile is used when walking the stack to check when we've got the first # caller stack frame. # _srcfile = os.path.normcase(currentframe.__code__.co_filename) # _srcfile is only used in conjunction with sys._getframe(). # To provide compatibility with older versions of Python, set _srcfile # to None if _getframe() is not available; this value will prevent # findCaller() from being called. #if not hasattr(sys, "_getframe"): # _srcfile = None # #_startTime is used as the base when calculating the relative time of events # _startTime = time.time() # #raiseExceptions is used to see if exceptions during handling should be #propagated # raiseExceptions = 1 # # If you don't want threading information in the log, set this to zero # logThreads = 1 # # If you don't want multiprocessing information in the log, set this to zero # logMultiprocessing = 1 # # If you don't want process information in the log, set this to zero # logProcesses = 1 #--------------------------------------------------------------------------- # Level related stuff #--------------------------------------------------------------------------- # # Default levels and level names, these can be replaced with any positive set # of values having corresponding names. There is a pseudo-level, NOTSET, which # is only really there as a lower limit for user-defined levels. Handlers and # loggers are initialized with NOTSET so that they will log all messages, even # at user-defined levels. # CRITICAL = 50 FATAL = CRITICAL ERROR = 40 WARNING = 30 WARN = WARNING INFO = 20 DEBUG = 10 NOTSET = 0 _levelNames = { CRITICAL : 'CRITICAL', ERROR : 'ERROR', WARNING : 'WARNING', INFO : 'INFO', DEBUG : 'DEBUG', NOTSET : 'NOTSET', 'CRITICAL' : CRITICAL, 'ERROR' : ERROR, 'WARN' : WARNING, 'WARNING' : WARNING, 'INFO' : INFO, 'DEBUG' : DEBUG, 'NOTSET' : NOTSET, } def getLevelName(level): """ Return the textual representation of logging level 'level'. If the level is one of the predefined levels (CRITICAL, ERROR, WARNING, INFO, DEBUG) then you get the corresponding string. If you have associated levels with names using addLevelName then the name you have associated with 'level' is returned. If a numeric value corresponding to one of the defined levels is passed in, the corresponding string representation is returned. Otherwise, the string "Level %s" % level is returned. """ return _levelNames.get(level, ("Level %s" % level)) def addLevelName(level, levelName): """ Associate 'levelName' with 'level'. This is used when converting levels to text during message formatting. """ _acquireLock() try: #unlikely to cause an exception, but you never know... _levelNames[level] = levelName _levelNames[levelName] = level finally: _releaseLock() def _checkLevel(level): if isinstance(level, (int, long)): rv = level elif str(level) == level: if level not in _levelNames: raise ValueError("Unknown level: %r" % level) rv = _levelNames[level] else: raise TypeError("Level not an integer or a valid string: %r" % level) return rv #--------------------------------------------------------------------------- # Thread-related stuff #--------------------------------------------------------------------------- # #_lock is used to serialize access to shared data structures in this module. #This needs to be an RLock because fileConfig() creates and configures #Handlers, and so might arbitrary user threads. Since Handler code updates the #shared dictionary _handlers, it needs to acquire the lock. But if configuring, #the lock would already have been acquired - so we need an RLock. #The same argument applies to Loggers and Manager.loggerDict. # if thread: _lock = threading.RLock() else: _lock = None def _acquireLock(): """ Acquire the module-level lock for serializing access to shared data. This should be released with _releaseLock(). """ if _lock: _lock.acquire() def _releaseLock(): """ Release the module-level lock acquired by calling _acquireLock(). """ if _lock: _lock.release() #--------------------------------------------------------------------------- # The logging record #--------------------------------------------------------------------------- class LogRecord(object): """ A LogRecord instance represents an event being logged. LogRecord instances are created every time something is logged. They contain all the information pertinent to the event being logged. The main information passed in is in msg and args, which are combined using str(msg) % args to create the message field of the record. The record also includes information such as when the record was created, the source line where the logging call was made, and any exception information to be logged. """ def __init__(self, name, level, pathname, lineno, msg, args, exc_info, func=None): """ Initialize a logging record with interesting information. """ ct = time.time() self.name = name self.msg = msg # # The following statement allows passing of a dictionary as a sole # argument, so that you can do something like # logging.debug("a %(a)d b %(b)s", {'a':1, 'b':2}) # Suggested by Stefan Behnel. # Note that without the test for args[0], we get a problem because # during formatting, we test to see if the arg is present using # 'if self.args:'. If the event being logged is e.g. 'Value is %d' # and if the passed arg fails 'if self.args:' then no formatting # is done. For example, logger.warn('Value is %d', 0) would log # 'Value is %d' instead of 'Value is 0'. # For the use case of passing a dictionary, this should not be a # problem. # Issue #21172: a request was made to relax the isinstance check # to hasattr(args[0], '__getitem__'). However, the docs on string # formatting still seem to suggest a mapping object is required. # Thus, while not removing the isinstance check, it does now look # for collections.Mapping rather than, as before, dict. if (args and len(args) == 1 and isinstance(args[0], collections.Mapping) and args[0]): args = args[0] self.args = args self.levelname = getLevelName(level) self.levelno = level self.pathname = pathname try: self.filename = os.path.basename(pathname) self.module = os.path.splitext(self.filename)[0] except (TypeError, ValueError, AttributeError): self.filename = pathname self.module = "Unknown module" self.exc_info = exc_info self.exc_text = None # used to cache the traceback text self.lineno = lineno self.funcName = func self.created = ct self.msecs = (ct - long(ct)) * 1000 self.relativeCreated = (self.created - _startTime) * 1000 if logThreads and thread: self.thread = thread.get_ident() self.threadName = threading.current_thread().name else: self.thread = None self.threadName = None if not logMultiprocessing: self.processName = None else: self.processName = 'MainProcess' mp = sys.modules.get('multiprocessing') if mp is not None: # Errors may occur if multiprocessing has not finished loading # yet - e.g. if a custom import hook causes third-party code # to run when multiprocessing calls import. See issue 8200 # for an example try: self.processName = mp.current_process().name except StandardError: pass if logProcesses and hasattr(os, 'getpid'): self.process = os.getpid() else: self.process = None def __str__(self): return '<LogRecord: %s, %s, %s, %s, "%s">'%(self.name, self.levelno, self.pathname, self.lineno, self.msg) def getMessage(self): """ Return the message for this LogRecord. Return the message for this LogRecord after merging any user-supplied arguments with the message. """ if not _unicode: #if no unicode support... msg = str(self.msg) else: msg = self.msg if not isinstance(msg, basestring): try: msg = str(self.msg) except UnicodeError: msg = self.msg #Defer encoding till later if self.args: msg = msg % self.args return msg def makeLogRecord(dict): """ Make a LogRecord whose attributes are defined by the specified dictionary, This function is useful for converting a logging event received over a socket connection (which is sent as a dictionary) into a LogRecord instance. """ rv = LogRecord(None, None, "", 0, "", (), None, None) rv.__dict__.update(dict) return rv #--------------------------------------------------------------------------- # Formatter classes and functions #--------------------------------------------------------------------------- class Formatter(object): """ Formatter instances are used to convert a LogRecord to text. Formatters need to know how a LogRecord is constructed. They are responsible for converting a LogRecord to (usually) a string which can be interpreted by either a human or an external system. The base Formatter allows a formatting string to be specified. If none is supplied, the default value of "%s(message)\\n" is used. The Formatter can be initialized with a format string which makes use of knowledge of the LogRecord attributes - e.g. the default value mentioned above makes use of the fact that the user's message and arguments are pre- formatted into a LogRecord's message attribute. Currently, the useful attributes in a LogRecord are described by: %(name)s Name of the logger (logging channel) %(levelno)s Numeric logging level for the message (DEBUG, INFO, WARNING, ERROR, CRITICAL) %(levelname)s Text logging level for the message ("DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL") %(pathname)s Full pathname of the source file where the logging call was issued (if available) %(filename)s Filename portion of pathname %(module)s Module (name portion of filename) %(lineno)d Source line number where the logging call was issued (if available) %(funcName)s Function name %(created)f Time when the LogRecord was created (time.time() return value) %(asctime)s Textual time when the LogRecord was created %(msecs)d Millisecond portion of the creation time %(relativeCreated)d Time in milliseconds when the LogRecord was created, relative to the time the logging module was loaded (typically at application startup time) %(thread)d Thread ID (if available) %(threadName)s Thread name (if available) %(process)d Process ID (if available) %(message)s The result of record.getMessage(), computed just as the record is emitted """ converter = time.localtime def __init__(self, fmt=None, datefmt=None): """ Initialize the formatter with specified format strings. Initialize the formatter either with the specified format string, or a default as described above. Allow for specialized date formatting with the optional datefmt argument (if omitted, you get the ISO8601 format). """ if fmt: self._fmt = fmt else: self._fmt = "%(message)s" self.datefmt = datefmt def formatTime(self, record, datefmt=None): """ Return the creation time of the specified LogRecord as formatted text. This method should be called from format() by a formatter which wants to make use of a formatted time. This method can be overridden in formatters to provide for any specific requirement, but the basic behaviour is as follows: if datefmt (a string) is specified, it is used with time.strftime() to format the creation time of the record. Otherwise, the ISO8601 format is used. The resulting string is returned. This function uses a user-configurable function to convert the creation time to a tuple. By default, time.localtime() is used; to change this for a particular formatter instance, set the 'converter' attribute to a function with the same signature as time.localtime() or time.gmtime(). To change it for all formatters, for example if you want all logging times to be shown in GMT, set the 'converter' attribute in the Formatter class. """ ct = self.converter(record.created) if datefmt: s = time.strftime(datefmt, ct) else: t = time.strftime("%Y-%m-%d %H:%M:%S", ct) s = "%s,%03d" % (t, record.msecs) return s def formatException(self, ei): """ Format and return the specified exception information as a string. This default implementation just uses traceback.print_exception() """ sio = cStringIO.StringIO() traceback.print_exception(ei[0], ei[1], ei[2], None, sio) s = sio.getvalue() sio.close() if s[-1:] == "\n": s = s[:-1] return s def usesTime(self): """ Check if the format uses the creation time of the record. """ return self._fmt.find("%(asctime)") >= 0 def format(self, record): """ Format the specified record as text. The record's attribute dictionary is used as the operand to a string formatting operation which yields the returned string. Before formatting the dictionary, a couple of preparatory steps are carried out. The message attribute of the record is computed using LogRecord.getMessage(). If the formatting string uses the time (as determined by a call to usesTime(), formatTime() is called to format the event time. If there is exception information, it is formatted using formatException() and appended to the message. """ record.message = record.getMessage() if self.usesTime(): record.asctime = self.formatTime(record, self.datefmt) try: s = self._fmt % record.__dict__ except UnicodeDecodeError as e: # Issue 25664. The logger name may be Unicode. Try again ... try: record.name = record.name.decode('utf-8') s = self._fmt % record.__dict__ except UnicodeDecodeError: raise e if record.exc_info: # Cache the traceback text to avoid converting it multiple times # (it's constant anyway) if not record.exc_text: record.exc_text = self.formatException(record.exc_info) if record.exc_text: if s[-1:] != "\n": s = s + "\n" try: s = s + record.exc_text except UnicodeError: # Sometimes filenames have non-ASCII chars, which can lead # to errors when s is Unicode and record.exc_text is str # See issue 8924. # We also use replace for when there are multiple # encodings, e.g. UTF-8 for the filesystem and latin-1 # for a script. See issue 13232. s = s + record.exc_text.decode(sys.getfilesystemencoding(), 'replace') return s # # The default formatter to use when no other is specified # _defaultFormatter = Formatter() class BufferingFormatter(object): """ A formatter suitable for formatting a number of records. """ def __init__(self, linefmt=None): """ Optionally specify a formatter which will be used to format each individual record. """ if linefmt: self.linefmt = linefmt else: self.linefmt = _defaultFormatter def formatHeader(self, records): """ Return the header string for the specified records. """ return "" def formatFooter(self, records): """ Return the footer string for the specified records. """ return "" def format(self, records): """ Format the specified records and return the result as a string. """ rv = "" if len(records) > 0: rv = rv + self.formatHeader(records) for record in records: rv = rv + self.linefmt.format(record) rv = rv + self.formatFooter(records) return rv #--------------------------------------------------------------------------- # Filter classes and functions #--------------------------------------------------------------------------- class Filter(object): """ Filter instances are used to perform arbitrary filtering of LogRecords. Loggers and Handlers can optionally use Filter instances to filter records as desired. The base filter class only allows events which are below a certain point in the logger hierarchy. For example, a filter initialized with "A.B" will allow events logged by loggers "A.B", "A.B.C", "A.B.C.D", "A.B.D" etc. but not "A.BB", "B.A.B" etc. If initialized with the empty string, all events are passed. """ def __init__(self, name=''): """ Initialize a filter. Initialize with the name of the logger which, together with its children, will have its events allowed through the filter. If no name is specified, allow every event. """ self.name = name self.nlen = len(name) def filter(self, record): """ Determine if the specified record is to be logged. Is the specified record to be logged? Returns 0 for no, nonzero for yes. If deemed appropriate, the record may be modified in-place. """ if self.nlen == 0: return 1 elif self.name == record.name: return 1 elif record.name.find(self.name, 0, self.nlen) != 0: return 0 return (record.name[self.nlen] == ".") class Filterer(object): """ A base class for loggers and handlers which allows them to share common code. """ def __init__(self): """ Initialize the list of filters to be an empty list. """ self.filters = [] def addFilter(self, filter): """ Add the specified filter to this handler. """ if not (filter in self.filters): self.filters.append(filter) def removeFilter(self, filter): """ Remove the specified filter from this handler. """ if filter in self.filters: self.filters.remove(filter) def filter(self, record): """ Determine if a record is loggable by consulting all the filters. The default is to allow the record to be logged; any filter can veto this and the record is then dropped. Returns a zero value if a record is to be dropped, else non-zero. """ rv = 1 for f in self.filters: if not f.filter(record): rv = 0 break return rv #--------------------------------------------------------------------------- # Handler classes and functions #--------------------------------------------------------------------------- _handlers = weakref.WeakValueDictionary() #map of handler names to handlers _handlerList = [] # added to allow handlers to be removed in reverse of order initialized def _removeHandlerRef(wr): """ Remove a handler reference from the internal cleanup list. """ # This function can be called during module teardown, when globals are # set to None. It can also be called from another thread. So we need to # pre-emptively grab the necessary globals and check if they're None, # to prevent race conditions and failures during interpreter shutdown. acquire, release, handlers = _acquireLock, _releaseLock, _handlerList if acquire and release and handlers: try: acquire() try: if wr in handlers: handlers.remove(wr) finally: release() except TypeError: # https://bugs.python.org/issue21149 - If the RLock object behind # acquire() and release() has been partially finalized you may see # an error about NoneType not being callable. Absolutely nothing # we can do in this GC during process shutdown situation. Eat it. pass def _addHandlerRef(handler): """ Add a handler to the internal cleanup list using a weak reference. """ _acquireLock() try: _handlerList.append(weakref.ref(handler, _removeHandlerRef)) finally: _releaseLock() class Handler(Filterer): """ Handler instances dispatch logging events to specific destinations. The base handler class. Acts as a placeholder which defines the Handler interface. Handlers can optionally use Formatter instances to format records as desired. By default, no formatter is specified; in this case, the 'raw' message as determined by record.message is logged. """ def __init__(self, level=NOTSET): """ Initializes the instance - basically setting the formatter to None and the filter list to empty. """ Filterer.__init__(self) self._name = None self.level = _checkLevel(level) self.formatter = None # Add the handler to the global _handlerList (for cleanup on shutdown) _addHandlerRef(self) self.createLock() def get_name(self): return self._name def set_name(self, name): _acquireLock() try: if self._name in _handlers: del _handlers[self._name] self._name = name if name: _handlers[name] = self finally: _releaseLock() name = property(get_name, set_name) def createLock(self): """ Acquire a thread lock for serializing access to the underlying I/O. """ if thread: self.lock = threading.RLock() else: self.lock = None def acquire(self): """ Acquire the I/O thread lock. """ if self.lock: self.lock.acquire() def release(self): """ Release the I/O thread lock. """ if self.lock: self.lock.release() def setLevel(self, level): """ Set the logging level of this handler. """ self.level = _checkLevel(level) def format(self, record): """ Format the specified record. If a formatter is set, use it. Otherwise, use the default formatter for the module. """ if self.formatter: fmt = self.formatter else: fmt = _defaultFormatter return fmt.format(record) def emit(self, record): """ Do whatever it takes to actually log the specified logging record. This version is intended to be implemented by subclasses and so raises a NotImplementedError. """ raise NotImplementedError('emit must be implemented ' 'by Handler subclasses') def handle(self, record): """ Conditionally emit the specified logging record. Emission depends on filters which may have been added to the handler. Wrap the actual emission of the record with acquisition/release of the I/O thread lock. Returns whether the filter passed the record for emission. """ rv = self.filter(record) if rv: self.acquire() try: self.emit(record) finally: self.release() return rv def setFormatter(self, fmt): """ Set the formatter for this handler. """ self.formatter = fmt def flush(self): """ Ensure all logging output has been flushed. This version does nothing and is intended to be implemented by subclasses. """ pass def close(self): """ Tidy up any resources used by the handler. This version removes the handler from an internal map of handlers, _handlers, which is used for handler lookup by name. Subclasses should ensure that this gets called from overridden close() methods. """ #get the module data lock, as we're updating a shared structure. _acquireLock() try: #unlikely to raise an exception, but you never know... if self._name and self._name in _handlers: del _handlers[self._name] finally: _releaseLock() def handleError(self, record): """ Handle errors which occur during an emit() call. This method should be called from handlers when an exception is encountered during an emit() call. If raiseExceptions is false, exceptions get silently ignored. This is what is mostly wanted for a logging system - most users will not care about errors in the logging system, they are more interested in application errors. You could, however, replace this with a custom handler if you wish. The record which was being processed is passed in to this method. """ if raiseExceptions and sys.stderr: # see issue 13807 ei = sys.exc_info() try: traceback.print_exception(ei[0], ei[1], ei[2], None, sys.stderr) sys.stderr.write('Logged from file %s, line %s\n' % ( record.filename, record.lineno)) except IOError: pass # see issue 5971 finally: del ei class StreamHandler(Handler): """ A handler class which writes logging records, appropriately formatted, to a stream. Note that this class does not close the stream, as sys.stdout or sys.stderr may be used. """ def __init__(self, stream=None): """ Initialize the handler. If stream is not specified, sys.stderr is used. """ Handler.__init__(self) if stream is None: stream = sys.stderr self.stream = stream def flush(self): """ Flushes the stream. """ self.acquire() try: if self.stream and hasattr(self.stream, "flush"): self.stream.flush() finally: self.release() def emit(self, record): """ Emit a record. If a formatter is specified, it is used to format the record. The record is then written to the stream with a trailing newline. If exception information is present, it is formatted using traceback.print_exception and appended to the stream. If the stream has an 'encoding' attribute, it is used to determine how to do the output to the stream. """ try: msg = self.format(record) stream = self.stream fs = "%s\n" if not _unicode: #if no unicode support... stream.write(fs % msg) else: try: if (isinstance(msg, unicode) and getattr(stream, 'encoding', None)): ufs = u'%s\n' try: stream.write(ufs % msg) except UnicodeEncodeError: #Printing to terminals sometimes fails. For example, #with an encoding of 'cp1251', the above write will #work if written to a stream opened or wrapped by #the codecs module, but fail when writing to a #terminal even when the codepage is set to cp1251. #An extra encoding step seems to be needed. stream.write((ufs % msg).encode(stream.encoding)) else: stream.write(fs % msg) except UnicodeError: stream.write(fs % msg.encode("UTF-8")) self.flush() except (KeyboardInterrupt, SystemExit): raise except: self.handleError(record) class FileHandler(StreamHandler): """ A handler class which writes formatted logging records to disk files. """ def __init__(self, filename, mode='a', encoding=None, delay=0): """ Open the specified file and use it as the stream for logging. """ #keep the absolute path, otherwise derived classes which use this #may come a cropper when the current directory changes if codecs is None: encoding = None self.baseFilename = os.path.abspath(filename) self.mode = mode self.encoding = encoding self.delay = delay if delay: #We don't open the stream, but we still need to call the #Handler constructor to set level, formatter, lock etc. Handler.__init__(self) self.stream = None else: StreamHandler.__init__(self, self._open()) def close(self): """ Closes the stream. """ self.acquire() try: try: if self.stream: try: self.flush() finally: stream = self.stream self.stream = None if hasattr(stream, "close"): stream.close() finally: # Issue #19523: call unconditionally to # prevent a handler leak when delay is set StreamHandler.close(self) finally: self.release() def _open(self): """ Open the current base file with the (original) mode and encoding. Return the resulting stream. """ if self.encoding is None: stream = open(self.baseFilename, self.mode) else: stream = codecs.open(self.baseFilename, self.mode, self.encoding) return stream def emit(self, record): """ Emit a record. If the stream was not opened because 'delay' was specified in the constructor, open it before calling the superclass's emit. """ if self.stream is None: self.stream = self._open() StreamHandler.emit(self, record) #--------------------------------------------------------------------------- # Manager classes and functions #--------------------------------------------------------------------------- class PlaceHolder(object): """ PlaceHolder instances are used in the Manager logger hierarchy to take the place of nodes for which no loggers have been defined. This class is intended for internal use only and not as part of the public API. """ def __init__(self, alogger): """ Initialize with the specified logger being a child of this placeholder. """ #self.loggers = [alogger] self.loggerMap = { alogger : None } def append(self, alogger): """ Add the specified logger as a child of this placeholder. """ #if alogger not in self.loggers: if alogger not in self.loggerMap: #self.loggers.append(alogger) self.loggerMap[alogger] = None # # Determine which class to use when instantiating loggers. # _loggerClass = None def setLoggerClass(klass): """ Set the class to be used when instantiating a logger. The class should define __init__() such that only a name argument is required, and the __init__() should call Logger.__init__() """ if klass != Logger: if not issubclass(klass, Logger): raise TypeError("logger not derived from logging.Logger: " + klass.__name__) global _loggerClass _loggerClass = klass def getLoggerClass(): """ Return the class to be used when instantiating a logger. """ return _loggerClass class Manager(object): """ There is [under normal circumstances] just one Manager instance, which holds the hierarchy of loggers. """ def __init__(self, rootnode): """ Initialize the manager with the root node of the logger hierarchy. """ self.root = rootnode self.disable = 0 self.emittedNoHandlerWarning = 0 self.loggerDict = {} self.loggerClass = None def getLogger(self, name): """ Get a logger with the specified name (channel name), creating it if it doesn't yet exist. This name is a dot-separated hierarchical name, such as "a", "a.b", "a.b.c" or similar. If a PlaceHolder existed for the specified name [i.e. the logger didn't exist but a child of it did], replace it with the created logger and fix up the parent/child references which pointed to the placeholder to now point to the logger. """ rv = None if not isinstance(name, basestring): raise TypeError('A logger name must be string or Unicode') if isinstance(name, unicode): name = name.encode('utf-8') _acquireLock() try: if name in self.loggerDict: rv = self.loggerDict[name] if isinstance(rv, PlaceHolder): ph = rv rv = (self.loggerClass or _loggerClass)(name) rv.manager = self self.loggerDict[name] = rv self._fixupChildren(ph, rv) self._fixupParents(rv) else: rv = (self.loggerClass or _loggerClass)(name) rv.manager = self self.loggerDict[name] = rv self._fixupParents(rv) finally: _releaseLock() return rv def setLoggerClass(self, klass): """ Set the class to be used when instantiating a logger with this Manager. """ if klass != Logger: if not issubclass(klass, Logger): raise TypeError("logger not derived from logging.Logger: " + klass.__name__) self.loggerClass = klass def _fixupParents(self, alogger): """ Ensure that there are either loggers or placeholders all the way from the specified logger to the root of the logger hierarchy. """ name = alogger.name i = name.rfind(".") rv = None while (i > 0) and not rv: substr = name[:i] if substr not in self.loggerDict: self.loggerDict[substr] = PlaceHolder(alogger) else: obj = self.loggerDict[substr] if isinstance(obj, Logger): rv = obj else: assert isinstance(obj, PlaceHolder) obj.append(alogger) i = name.rfind(".", 0, i - 1) if not rv: rv = self.root alogger.parent = rv def _fixupChildren(self, ph, alogger): """ Ensure that children of the placeholder ph are connected to the specified logger. """ name = alogger.name namelen = len(name) for c in ph.loggerMap.keys(): #The if means ... if not c.parent.name.startswith(nm) if c.parent.name[:namelen] != name: alogger.parent = c.parent c.parent = alogger #--------------------------------------------------------------------------- # Logger classes and functions #--------------------------------------------------------------------------- class Logger(Filterer): """ Instances of the Logger class represent a single logging channel. A "logging channel" indicates an area of an application. Exactly how an "area" is defined is up to the application developer. Since an application can have any number of areas, logging channels are identified by a unique string. Application areas can be nested (e.g. an area of "input processing" might include sub-areas "read CSV files", "read XLS files" and "read Gnumeric files"). To cater for this natural nesting, channel names are organized into a namespace hierarchy where levels are separated by periods, much like the Java or Python package namespace. So in the instance given above, channel names might be "input" for the upper level, and "input.csv", "input.xls" and "input.gnu" for the sub-levels. There is no arbitrary limit to the depth of nesting. """ def __init__(self, name, level=NOTSET): """ Initialize the logger with a name and an optional level. """ Filterer.__init__(self) self.name = name self.level = _checkLevel(level) self.parent = None self.propagate = 1 self.handlers = [] self.disabled = 0 def setLevel(self, level): """ Set the logging level of this logger. """ self.level = _checkLevel(level) def debug(self, msg, *args, **kwargs): """ Log 'msg % args' with severity 'DEBUG'. To pass exception information, use the keyword argument exc_info with a true value, e.g. logger.debug("Houston, we have a %s", "thorny problem", exc_info=1) """ if self.isEnabledFor(DEBUG): self._log(DEBUG, msg, args, **kwargs) def info(self, msg, *args, **kwargs): """ Log 'msg % args' with severity 'INFO'. To pass exception information, use the keyword argument exc_info with a true value, e.g. logger.info("Houston, we have a %s", "interesting problem", exc_info=1) """ if self.isEnabledFor(INFO): self._log(INFO, msg, args, **kwargs) def warning(self, msg, *args, **kwargs): """ Log 'msg % args' with severity 'WARNING'. To pass exception information, use the keyword argument exc_info with a true value, e.g. logger.warning("Houston, we have a %s", "bit of a problem", exc_info=1) """ if self.isEnabledFor(WARNING): self._log(WARNING, msg, args, **kwargs) warn = warning def error(self, msg, *args, **kwargs): """ Log 'msg % args' with severity 'ERROR'. To pass exception information, use the keyword argument exc_info with a true value, e.g. logger.error("Houston, we have a %s", "major problem", exc_info=1) """ if self.isEnabledFor(ERROR): self._log(ERROR, msg, args, **kwargs) def exception(self, msg, *args, **kwargs): """ Convenience method for logging an ERROR with exception information. """ kwargs['exc_info'] = 1 self.error(msg, *args, **kwargs) def critical(self, msg, *args, **kwargs): """ Log 'msg % args' with severity 'CRITICAL'. To pass exception information, use the keyword argument exc_info with a true value, e.g. logger.critical("Houston, we have a %s", "major disaster", exc_info=1) """ if self.isEnabledFor(CRITICAL): self._log(CRITICAL, msg, args, **kwargs) fatal = critical def log(self, level, msg, *args, **kwargs): """ Log 'msg % args' with the integer severity 'level'. To pass exception information, use the keyword argument exc_info with a true value, e.g. logger.log(level, "We have a %s", "mysterious problem", exc_info=1) """ if not isinstance(level, (int, long)): if raiseExceptions: raise TypeError("level must be an integer") else: return if self.isEnabledFor(level): self._log(level, msg, args, **kwargs) def findCaller(self): """ Find the stack frame of the caller so that we can note the source file name, line number and function name. """ f = currentframe() #On some versions of IronPython, currentframe() returns None if #IronPython isn't run with -X:Frames. if f is not None: f = f.f_back rv = "(unknown file)", 0, "(unknown function)" while hasattr(f, "f_code"): co = f.f_code filename = os.path.normcase(co.co_filename) if filename == _srcfile: f = f.f_back continue rv = (co.co_filename, f.f_lineno, co.co_name) break return rv def makeRecord(self, name, level, fn, lno, msg, args, exc_info, func=None, extra=None): """ A factory method which can be overridden in subclasses to create specialized LogRecords. """ rv = LogRecord(name, level, fn, lno, msg, args, exc_info, func) if extra is not None: for key in extra: if (key in ["message", "asctime"]) or (key in rv.__dict__): raise KeyError("Attempt to overwrite %r in LogRecord" % key) rv.__dict__[key] = extra[key] return rv def _log(self, level, msg, args, exc_info=None, extra=None): """ Low-level logging routine which creates a LogRecord and then calls all the handlers of this logger to handle the record. """ if _srcfile: #IronPython doesn't track Python frames, so findCaller raises an #exception on some versions of IronPython. We trap it here so that #IronPython can use logging. try: fn, lno, func = self.findCaller() except ValueError: fn, lno, func = "(unknown file)", 0, "(unknown function)" else: fn, lno, func = "(unknown file)", 0, "(unknown function)" if exc_info: if not isinstance(exc_info, tuple): exc_info = sys.exc_info() record = self.makeRecord(self.name, level, fn, lno, msg, args, exc_info, func, extra) self.handle(record) def handle(self, record): """ Call the handlers for the specified record. This method is used for unpickled records received from a socket, as well as those created locally. Logger-level filtering is applied. """ if (not self.disabled) and self.filter(record): self.callHandlers(record) def addHandler(self, hdlr): """ Add the specified handler to this logger. """ _acquireLock() try: if not (hdlr in self.handlers): self.handlers.append(hdlr) finally: _releaseLock() def removeHandler(self, hdlr): """ Remove the specified handler from this logger. """ _acquireLock() try: if hdlr in self.handlers: self.handlers.remove(hdlr) finally: _releaseLock() def callHandlers(self, record): """ Pass a record to all relevant handlers. Loop through all handlers for this logger and its parents in the logger hierarchy. If no handler was found, output a one-off error message to sys.stderr. Stop searching up the hierarchy whenever a logger with the "propagate" attribute set to zero is found - that will be the last logger whose handlers are called. """ c = self found = 0 while c: for hdlr in c.handlers: found = found + 1 if record.levelno >= hdlr.level: hdlr.handle(record) if not c.propagate: 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 def getEffectiveLevel(self): """ Get the effective level for this logger. Loop through this logger and its parents in the logger hierarchy, looking for a non-zero logging level. Return the first one found. """ logger = self while logger: if logger.level: return logger.level logger = logger.parent return NOTSET def isEnabledFor(self, level): """ Is this logger enabled for level 'level'? """ if self.manager.disable >= level: return 0 return level >= self.getEffectiveLevel() def getChild(self, suffix): """ Get a logger which is a descendant to this one. This is a convenience method, such that logging.getLogger('abc').getChild('def.ghi') is the same as logging.getLogger('abc.def.ghi') It's useful, for example, when the parent logger is named using __name__ rather than a literal string. """ if self.root is not self: suffix = '.'.join((self.name, suffix)) return self.manager.getLogger(suffix) class RootLogger(Logger): """ A root logger is not that different to any other logger, except that it must have a logging level and there is only one instance of it in the hierarchy. """ def __init__(self, level): """ Initialize the logger with the name "root". """ Logger.__init__(self, "root", level) _loggerClass = Logger class LoggerAdapter(object): """ An adapter for loggers which makes it easier to specify contextual information in logging output. """ def __init__(self, logger, extra): """ Initialize the adapter with a logger and a dict-like object which provides contextual information. This constructor signature allows easy stacking of LoggerAdapters, if so desired. You can effectively pass keyword arguments as shown in the following example: adapter = LoggerAdapter(someLogger, dict(p1=v1, p2="v2")) """ self.logger = logger self.extra = extra def process(self, msg, kwargs): """ Process the logging message and keyword arguments passed in to a logging call to insert contextual information. You can either manipulate the message itself, the keyword args or both. Return the message and kwargs modified (or not) to suit your needs. Normally, you'll only need to override this one method in a LoggerAdapter subclass for your specific needs. """ kwargs["extra"] = self.extra return msg, kwargs def debug(self, msg, *args, **kwargs): """ Delegate a debug call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.debug(msg, *args, **kwargs) def info(self, msg, *args, **kwargs): """ Delegate an info call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.info(msg, *args, **kwargs) def warning(self, msg, *args, **kwargs): """ Delegate a warning call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.warning(msg, *args, **kwargs) def error(self, msg, *args, **kwargs): """ Delegate an error call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.error(msg, *args, **kwargs) def exception(self, msg, *args, **kwargs): """ Delegate an exception call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) kwargs["exc_info"] = 1 self.logger.error(msg, *args, **kwargs) def critical(self, msg, *args, **kwargs): """ Delegate a critical call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.critical(msg, *args, **kwargs) def log(self, level, msg, *args, **kwargs): """ Delegate a log call to the underlying logger, after adding contextual information from this adapter instance. """ msg, kwargs = self.process(msg, kwargs) self.logger.log(level, msg, *args, **kwargs) def isEnabledFor(self, level): """ See if the underlying logger is enabled for the specified level. """ return self.logger.isEnabledFor(level) root = RootLogger(WARNING) Logger.root = root Logger.manager = Manager(Logger.root) #--------------------------------------------------------------------------- # Configuration classes and functions #--------------------------------------------------------------------------- BASIC_FORMAT = "%(levelname)s:%(name)s:%(message)s" def basicConfig(**kwargs): """ Do basic configuration for the logging system. This function does nothing if the root logger already has handlers configured. It is a convenience method intended for use by simple scripts to do one-shot configuration of the logging package. The default behaviour is to create a StreamHandler which writes to sys.stderr, set a formatter using the BASIC_FORMAT format string, and add the handler to the root logger. A number of optional keyword arguments may be specified, which can alter the default behaviour. filename Specifies that a FileHandler be created, using the specified filename, rather than a StreamHandler. filemode Specifies the mode to open the file, if filename is specified (if filemode is unspecified, it defaults to 'a'). format Use the specified format string for the handler. datefmt Use the specified date/time format. level Set the root logger level to the specified level. stream Use the specified stream to initialize the StreamHandler. Note that this argument is incompatible with 'filename' - if both are present, 'stream' is ignored. Note that you could specify a stream created using open(filename, mode) rather than passing the filename and mode in. However, it should be remembered that StreamHandler does not close its stream (since it may be using sys.stdout or sys.stderr), whereas FileHandler closes its stream when the handler is closed. """ # Add thread safety in case someone mistakenly calls # basicConfig() from multiple threads _acquireLock() try: if len(root.handlers) == 0: filename = kwargs.get("filename") if filename: mode = kwargs.get("filemode", 'a') hdlr = FileHandler(filename, mode) else: stream = kwargs.get("stream") hdlr = StreamHandler(stream) fs = kwargs.get("format", BASIC_FORMAT) dfs = kwargs.get("datefmt", None) fmt = Formatter(fs, dfs) hdlr.setFormatter(fmt) root.addHandler(hdlr) level = kwargs.get("level") if level is not None: root.setLevel(level) finally: _releaseLock() #--------------------------------------------------------------------------- # Utility functions at module level. # Basically delegate everything to the root logger. #--------------------------------------------------------------------------- def getLogger(name=None): """ Return a logger with the specified name, creating it if necessary. If no name is specified, return the root logger. """ if name: return Logger.manager.getLogger(name) else: return root #def getRootLogger(): # """ # Return the root logger. # # Note that getLogger('') now does the same thing, so this function is # deprecated and may disappear in the future. # """ # return root def critical(msg, *args, **kwargs): """ Log a message with severity 'CRITICAL' on the root logger. """ if len(root.handlers) == 0: basicConfig() root.critical(msg, *args, **kwargs) fatal = critical def error(msg, *args, **kwargs): """ Log a message with severity 'ERROR' on the root logger. """ if len(root.handlers) == 0: basicConfig() root.error(msg, *args, **kwargs) def exception(msg, *args, **kwargs): """ Log a message with severity 'ERROR' on the root logger, with exception information. """ kwargs['exc_info'] = 1 error(msg, *args, **kwargs) def warning(msg, *args, **kwargs): """ Log a message with severity 'WARNING' on the root logger. """ if len(root.handlers) == 0: basicConfig() root.warning(msg, *args, **kwargs) warn = warning def info(msg, *args, **kwargs): """ Log a message with severity 'INFO' on the root logger. """ if len(root.handlers) == 0: basicConfig() root.info(msg, *args, **kwargs) def debug(msg, *args, **kwargs): """ Log a message with severity 'DEBUG' on the root logger. """ if len(root.handlers) == 0: basicConfig() root.debug(msg, *args, **kwargs) def log(level, msg, *args, **kwargs): """ Log 'msg % args' with the integer severity 'level' on the root logger. """ if len(root.handlers) == 0: basicConfig() root.log(level, msg, *args, **kwargs) def disable(level): """ Disable all logging calls of severity 'level' and below. """ root.manager.disable = level def shutdown(handlerList=_handlerList): """ Perform any cleanup actions in the logging system (e.g. flushing buffers). Should be called at application exit. """ for wr in reversed(handlerList[:]): #errors might occur, for example, if files are locked #we just ignore them if raiseExceptions is not set try: h = wr() if h: try: h.acquire() h.flush() h.close() except (IOError, ValueError): # Ignore errors which might be caused # because handlers have been closed but # references to them are still around at # application exit. pass finally: h.release() except: if raiseExceptions: raise #else, swallow #Let's try and shutdown automatically on application exit... import atexit atexit.register(shutdown) # Null handler class NullHandler(Handler): """ This handler does nothing. It's intended to be used to avoid the "No handlers could be found for logger XXX" one-off warning. This is important for library code, which may contain code to log events. If a user of the library does not configure logging, the one-off warning might be produced; to avoid this, the library developer simply needs to instantiate a NullHandler and add it to the top-level logger of the library module or package. """ def handle(self, record): pass def emit(self, record): pass def createLock(self): self.lock = None # Warnings integration _warnings_showwarning = None def _showwarning(message, category, filename, lineno, file=None, line=None): """ Implementation of showwarnings which redirects to logging, which will first check to see if the file parameter is None. If a file is specified, it will delegate to the original warnings implementation of showwarning. Otherwise, it will call warnings.formatwarning and will log the resulting string to a warnings logger named "py.warnings" with level logging.WARNING. """ if file is not None: if _warnings_showwarning is not None: _warnings_showwarning(message, category, filename, lineno, file, line) else: s = warnings.formatwarning(message, category, filename, lineno, line) logger = getLogger("py.warnings") if not logger.handlers: logger.addHandler(NullHandler()) logger.warning("%s", s) def captureWarnings(capture): """ If capture is true, redirect all warnings to the logging package. If capture is False, ensure that warnings are not redirected to logging but to their original destinations. """ global _warnings_showwarning if capture: if _warnings_showwarning is None: _warnings_showwarning = warnings.showwarning warnings.showwarning = _showwarning else: if _warnings_showwarning is not None: warnings.showwarning = _warnings_showwarning _warnings_showwarning = None