Returns whether or not the resource is a directory.
        
        :return     <bool>

def isdir(self, relpath, rsc=None):
        """
        Returns whether or not the resource is a directory.
        
        :return     <bool>
        """
        filepath = self.find(relpath, rsc)
        if filepath.startswith(':'):
            resource = QtCore.QResource(filepath)
            return not resource.isFile()
        else:
            return os.path.isdir(filepath)