En Tue, 17 Feb 2009 21:12:57 -0200, J Kenneth King <ja...@agentultra.com>
escribió:
I recently started a project called TracShell
(http://code.google.com/p/tracshell) where I make heavy use of the
xmlrpclib core module.
When the number of RPC calls was small, wrapping each call in try/except
was acceptable. However, this obviously will duplicate code all over the
place. There are only ever two exceptions that the module itself will
throw: xmlrpclib.ProtocolError and xmlrpclib.Fault -- both very useful,
but not show stoppers.
To combat the duplication, my clever idea was to use a function
decorator to wrap any function that used xmlrpclib calls:
def catch_errors(fn):
"""
A decorator to catch typical xmlrpclib exceptions
"""
def wrapped(*args, **kwargs):
try:
return fn(*args, **kwargs)
except xmlrpclib.ProtocolError, e:
print "There was a problem communicating with the server."
print "URL: %s" % e.url
print "Headers: %s" % e.headers
print "Error code: %d" % e.errcode
print "Error message: %s" % e.errmsg
print "Please file a report with the TracShell developers."
pass
except xmlrpclib.Fault, e:
print "A fault ocurred"
print "Fault code: %d" % e.faultCode
print "Fault string: %s" % e.faultString
print "If you think this message is the result of an error,"
print "please file a report with the TracShell developers."
pass
return wrapped
I don't like the idea of "hiding" an exception. The caller code doesn't
know an exception occurred, and just continue doing its work, with bogus
results... is this what you want? Also, you don't include the stack trace
- and usually it contains very valuable information. When your users start
"filing a report with the TracShell developers" and you feel clueless, a
stack trace is important (you don't have to show it on screen - a log file
is even better).
If all you want is to customize the error message, use sys.except_hook
Looking into the code, those "pass" statement are useless; and error
messages are usually written to stderr instead of stdout.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
