nagiosplugin is a class library which helps writing Nagios (or
Icinga) compatible plugins easily in Python. It cares for much of the
boilerplate code and default logic commonly found in Nagios checks,
including:

 * Nagios 3 Plugin API compliant parameters and output formatting
 * Controller to handle the general plugin control flow
 * Full Nagios range syntax support
 * Automatic threshold checking
 * Multiple independend measures and overall state logic
 * Long output and performance data
 * Timeout handling
 * Default options
 * Persistent "cookies" to retain state information between check runs

WWW: http://projects.gocept.com/projects/nagiosplugin