|  | def set_append(d, var, val, sep=' '): | 
|  | values = (d.getVar(var, True) or '').split(sep) | 
|  | if filter(bool, values): | 
|  | d.appendVar(var, '%s%s' %(sep, val)) | 
|  | else: | 
|  | d.setVar(var, val) | 
|  |  | 
|  |  | 
|  | def listvar_to_list(d, list_var, sep=' '): | 
|  | return list(filter(bool, (d.getVar(list_var, True) or '').split(sep))) | 
|  |  | 
|  |  | 
|  | def compose_list(d, fmtvar, *listvars, **kw): | 
|  | import itertools | 
|  | fmt = d.getVar(fmtvar, True) | 
|  | lists = [listvar_to_list(d, x) for x in listvars] | 
|  | lst = [fmt.format(*x) for x in itertools.product(*lists)] | 
|  | return (kw.get('sep') or ' ').join(lst) | 
|  |  | 
|  |  | 
|  | def compose_list_zip(d, fmtvar, *listvars, **kw): | 
|  | fmt = d.getVar(fmtvar, True) | 
|  | lists = [listvar_to_list(d, x) for x in listvars] | 
|  | lst = [fmt.format(*x) for x in zip(*lists)] | 
|  | return (kw.get('sep') or ' ').join(lst) |