def getShortOption(self, longname):
        """
        Return the short option letter or None
        @return: C{str} or L{None}
        """
        optList = self.allOptionsNameToDefinition[longname]
        return optList[0] or None

        Return the short option letter or None
        @return: C{str} or L{None}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/_shellcomp.py