虽然循环问题。结果不是我所期望的

Question

总的来说，我是 Python 和 Stackoverflow 的新手，如果我的格式很糟糕而且我不擅长英语，我很抱歉。但我对这段代码有疑问。

n = int(input("Fibonacci sequence (2-10): "))
a = 0
b = 1
sum = 0
count = 1
f = True
print("Fibonacci sequence up to {}: ".format(n), end = " ") 
while(count <= n):
      print(sum, end = " ")
      count += 1
      a = b
      b = sum
      sum = a + b

这是代码的结果

Fibonacci sequence (2-10): 2
Fibonacci sequence up to 2: 0 1

这是我所期望的结果。

Fibonacci sequence (2-10): 1
Invalid Number!
Fibonacci sequence (2-10): 15
Invalid Number!
Fibonacci sequence (2-10): 10
Fibonacci sequence up to 10: 0 1 1 2 3 5 8 13 21 34

Answer 1

看起来您只需要添加一个额外的验证步骤以确保输入在所需的范围内。应该这样做。

while True:
    n = int(input("Fibonacci sequence (2-10): "))
    if n<2 or n>10:
        print("Invalid Number!")
    else:
        a = 0
        b = 1
        sum = 0
        count = 1
        f = True
        print("Fibonacci sequence up to {}: ".format(n), end = " ") 
        while(count <= n):
              print(sum, end = " ")
              count += 1
              a = b
              b = sum
              sum = a + b
        break

编辑：就@Barmar 而言，外部循环有助于避免在输入不在所需范围内时重新运行代码。