[Python-3000] Extending warnings for Py3K - any interest?

[Andrew Clover]

I've always felt slightly disappointed by the Python warnings interface. 
It's great for managing language feature deprecation, but I've often 
wanted something I could also use for recoverable errors in general.

I've written multiple application-specific mechanisms for allowing a 
caller to customise handling of potentially recoverable conditions in 
the past, so I think it's probably a fairly common use case, and maybe, 
if others how found the same, worth standardising as an extension of the 
existing Python warnings system.

Here's a first sketch of the sort of thing I'm thinking of:

   http://doxdesk.com/file/software/py/v/warnings2-0.1.py

Features:

   - warnings as instances with arbitrary properties, rather than being
     limited to a string message;

   - different severities with different default actions, so trivial
     warnings can be ignored by default and things which are by default
     errors can be recovered if a filter says so;

   - option to store warning instances that occur for later handling;

   - switchable warnings-handling contexts (like eg. the decimal module)
     for temporary changes to filters;

   - context manager helpers so you can say things like:

     with ignoring(DeprecationWarning):
         import oldmodule

     with storing(InvalidDataWarning) as problems:
         reghive.scanKeys()
     for problem in problems: ...

Anyone agree/disagree with the idea of adding such functionality to 
warnings, or what features are worthwhile?

-- 
And Clover
mailto:and at doxdesk.com
http://www.doxdesk.com/