The Python Plugin is very useful for encoding logic or operations into a build where a simple shell won't help. It would be nice if the Python Plugin would also work with Conditional BuildStep plugin so that the Python scripts could be conditionally executed. According to this web page (https://wiki.jenkins-ci.org/display/JENKINS/Conditional+BuildStep+Plugin), the problem is because the Python Plugin "does not provide a @DataBoundConstructor constructor and/or the Descriptor does not extend hudson.tasks.BuildStepDescriptor."