def signed_permutations(t):
 return (type(t)(i) for j in permutations(t) for i in permute_signs(j))

def signed_permutations ( t ) : return ( type ( t ) ( i ) for j in permutations ( t ) for i in permute_signs ( j ) )
return iterator in which the signs of non-zero elements of t and the order of the elements are permuted .