def is_longitudinal(self):
        """
        Returns
        -------
        boolean :
            longitudinal status of this project
        """
        return len(self.events) > 0 and \
            len(self.arm_nums) > 0 and \
            len(self.arm_names) > 0
def is_longitudinal ( self ) : return len ( self . events ) > 0 and len ( self . arm_nums ) > 0 and len ( self . arm_names ) > 0
Returns
        -------
        boolean :
            longitudinal status of this project