Warning Framework

The warning filter

  • Handling of each warning message can be modified
  • Warning filter specifies actions for individual warnings
  • Actions:
     'error'      Turn warning into exception
     'ignore'     Ignore the warning
     'always'     Always print the warning message
     'once'       Print warning message only once
     'default'    Print warning message once for location where
                  warning message is issued
     'module'     Print warning message once for each module 
                  where warning message is issued
  • warnings.filterwarnings(action [, message [, category [, module [, lineno]]]])
     action     = One of the above actions
     message    = Regular expression matching warning message
     category   = DeprecationWarning, SyntaxWarning, etc.
     module     = Regular expression matching module name
     lineno     = Line number matching location of warning
<<< O'Reilly OSCON 2001, New Features in Python 2, Slide 36
July 26, 2001, beazley@cs.uchicago.edu
>>>