[Python-checkins] python/nondist/peps pep-0337.txt, NONE,
1.1 pep-0000.txt, 1.295, 1.296
goodger at users.sourceforge.net
goodger at users.sourceforge.net
Sat Dec 11 21:01:11 CET 2004
Update of /cvsroot/python/python/nondist/peps
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv12330
Modified Files:
pep-0000.txt
Added Files:
pep-0337.txt
Log Message:
added PEP 337, Logging Usage in the Standard Library, by Michael P. Dubner
--- NEW FILE: pep-0337.txt ---
PEP: 337
Title: Logging Usage in the Standard Library
Version: $Revision: 1.1 $
Last-Modified: $Date: 2004/12/11 20:01:07 $
Author: Michael P. Dubner <dubnerm at mindless.com>
Status: Draft
Type: Standards Track
Content-Type: text/plain
Created: 02-Oct-2004
Python-Version: 2.5
Post-History: 10-Nov-2004
Abstract
This PEP defines a standard for using the logging system (PEP 282
[1]) in the standard library.
Implementing this PEP will simplify development of daemon
applications. As a downside this PEP requires slight
modifications (however in a back-portable way) to a large number
of standard modules.
After implementing this PEP one can use following filtering
scheme:
logging.getLogger('py.BaseHTTPServer').setLevel(logging.FATAL)
Rationale
There are a couple of situations when output to stdout or stderr
is impractical:
- Daemon applications where the framework doesn't allow the
redirection of standard output to some file, but assumes use of
some other form of logging. Examples are syslog under *nix'es
and EventLog under WinNT+.
- GUI applications which want to output every new log entry in
separate pop-up window (i.e. fading OSD).
Also sometimes applications want to filter output entries based on
their source or severity. This requirement can't be implemented
using simple redirection.
Finally sometimes output needs to be marked with event timestamps,
which can be accomplished with ease using the logging system.
Proposal
Every module usable for daemon and GUI applications should be
rewritten to use the logging system instead of 'print' or
'sys.stdout.write'.
There should be code like this included in the beginning of every
modified module:
import logging
_log = logging.getLogger('py.<module-name>')
A prefix of 'py.' [2] must be used by all modules included in the
standard library distributed along with Python, and only by such
modules (unverifiable). The use of "_log" is intentional as we
don't want to auto-export it. For modules that use log only in
one class a logger can be created inside the class definition as
follows:
class XXX:
__log = logging.getLogger('py.<module-name>')
Then this class can create access methods to log to this private
logger.
So "print" and "sys.std{out|err}.write" statements should be
replaced with "_log.{debug|info}", and "traceback.print_exception"
with "_log.exception" or sometimes "_log.debug('...', exc_info=1)".
Module List
Here is a (possibly incomplete) list of modules to be reworked:
- asyncore (dispatcher.log, dispatcher.log_info)
- BaseHTTPServer (BaseHTTPRequestHandler.log_request,
BaseHTTPRequestHandler.log_error,
BaseHTTPRequestHandler.log_message)
- cgi (possibly - is cgi.log used by somebody?)
- ftplib (if FTP.debugging)
- gopherlib (get_directory)
- httplib (HTTPResponse, HTTPConnection)
- ihooks (_Verbose)
- imaplib (IMAP4._mesg)
- mhlib (MH.error)
- nntplib (NNTP)
- pipes (Template.makepipeline)
- pkgutil (extend_path)
- platform (_syscmd_ver)
- poplib (if POP3._debugging)
- profile (if Profile.verbose)
- robotparser (_debug)
- smtplib (if SGMLParser.verbose)
- shlex (if shlex.debug)
- smtpd (SMTPChannel/PureProxy where print >> DEBUGSTREAM)
- smtplib (if SMTP.debuglevel)
- SocketServer (BaseServer.handle_error)
- telnetlib (if Telnet.debuglevel)
- threading? (_Verbose._note, Thread.__bootstrap)
- timeit (Timer.print_exc)
- trace
- uu (decode)
Additionally there are a couple of modules with commented debug
output or modules where debug output should be added. For
example:
- urllib
Finally possibly some modules should be extended to provide more
debug information.
Doubtful Modules
Listed here are modules that the community will propose for
addition to the module list and modules that the community say
should be removed from the module list.
- tabnanny (check)
Guidelines for Logging Usage
Also we can provide some recommendation to authors of library
modules so they all follow the same format of naming loggers. I
propose that non-standard library modules should use loggers named
after their full names, so a module "spam" in sub-package "junk"
of package "dummy" will be named "dummy.junk.spam" and, of course,
the "__init__" module of the same sub-package will have the logger
name "dummy.junk".
References
[1] PEP 282, A Logging System, Vinay Sajip, Trent Mick
http://www.python.org/peps/pep-0282.html
[2] http://mail.python.org/pipermail/python-dev/2004-October/049282.html
Copyright
This document has been placed in the public domain.
Local Variables:
mode: indented-text
indent-tabs-mode: nil
sentence-end-double-space: t
fill-column: 70
End:
Index: pep-0000.txt
===================================================================
RCS file: /cvsroot/python/python/nondist/peps/pep-0000.txt,v
retrieving revision 1.295
retrieving revision 1.296
diff -u -d -r1.295 -r1.296
--- pep-0000.txt 30 Nov 2004 13:44:08 -0000 1.295
+++ pep-0000.txt 11 Dec 2004 20:01:08 -0000 1.296
@@ -123,6 +123,7 @@
S 334 Simple Coroutines via SuspendIteration Evans
S 335 Overloadable Boolean Operators Ewing
S 336 Make None Callable McClelland
+ S 337 Logging Usage in the Standard Library Dubner
S 754 IEEE 754 Floating Point Special Values Warnes
Finished PEPs (done, implemented in CVS)
@@ -368,6 +369,7 @@
S 334 Simple Coroutines via SuspendIteration Evans
S 335 Overloadable Boolean Operators Ewing
S 336 Make None Callable McClelland
+ S 337 Logging Usage in the Standard Library Dubner
SR 666 Reject Foolish Indentation Creighton
S 754 IEEE 754 Floating Point Special Values Warnes
I 3000 Python 3.0 Plans Kuchling, Cannon
@@ -405,6 +407,7 @@
Creighton, Laura lac at strakt.com
Dörwald, Walter
Drake, Fred fdrake at acm.org
+ Dubner, Michael P. dubnerm at mindless.com
Dubois, Paul F. paul at pfdubois.com
Eby, Phillip J. pje at telecommunity.com
Epler, Jeff jepler at unpythonic.net
More information about the Python-checkins
mailing list