namelist : namelist ',' NAME \n | NAME

def p_namelist(self,t):
    "namelist : namelist ',' NAME \n | NAME"
    if len(t)==2: t[0] = [t[1]]
    elif len(t)==4: t[0] = t[1] + [t[3]]
    else: raise NotImplementedError('unk_len',len(t)) # pragma: no cover