def dict_from_expr(expr, **args):
 (rep, opt) = _dict_from_expr(expr, build_options(args))
 return (rep, opt.gens)

def dict_from_expr ( expr , ** args ) : ( rep , opt ) = _dict_from_expr ( expr , build_options ( args ) ) return ( rep , opt . gens )
transform an expression into a multinomial form .