import pyblish.api
​
​
class OpenInExplorer(pyblish.api.Action):
    label = "Open in Explorer"
    on = "failed" plug-in
    icon = "hand-o-up"
​
    def process(self, context):
        import subprocess
        subprocess.call("start .", shell=True)
​
​
class Validate(pyblish.api.Validator):
    actions = [
        # Order of items is preserved
        pyblish.api.Category("My Actions"),
        MyAction,
        pyblish.api.Separator,
    ]
​
    def process(self, context, plugin):
        raise Exception("Failed")