问如何在范围外获取数字

EN

first, last = tuple(map(int, input("what are first and last numbers?").split(" ")))
data = set(range(first, last + 1))
while True:
    inp = input("entre set: ")
    if inp == "":
        break
    first, last = tuple(map(int, inp.split(" ")))
    numbers_set = set(range(first, last + 1))
    data -= numbers_set
    
data = tuple(data)
last_var = data[0]
res = str(data[0])

for var in data[1:]:
    if var != last_var + 1:
        res += "-" + str(last_var) + ", " + str(var)
    last_var = var
res += "-" + str(last_var)
print(res)

>>> r = set(range(1,21)) # numbers 1-20
>>> r
{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
>>> q = set(range(3,9)) | set(range(11,16)) #numbers 3-8 and 11-15
>>> q
{3, 4, 5, 6, 7, 8, 11, 12, 13, 14}
>>> r-q # Difference of sets (elements in r that are not in q)
{1, 2, 9, 10, 15, 16, 17, 18, 19, 20}