python 接收輸入（字符串轉數字）

n = input('please input a number:')

這樣默認接收的是字符串，

如下代碼就會報錯：

n = input('please input a number:')
sum = 0
counter = 1
while counter <= n:
    sum = sum + counter
    counter += 1

print("1 到 %d 之和爲: %d" % (n,sum))

 

改成如下：

n = int(input('please input a number:'))
sum = 0
counter = 1
while counter <= n:
    sum = sum + counter
    counter += 1

print("1 到 %d 之和爲: %d" % (n,sum))