从键盘输入正整数n 计算1+2+3……+n的值

n = int(input('Input n:'))
sum = 0
for i in range(1, n+1, 1):
    sum += i
print('sum={}'.format(sum))

有用采纳~

n = int(input("Input n:"))
print("sum={}".format(sum(range(1, n+1)))

或

n = int(input("Input n:"))

print("sum=%d".%(sum(range(1, n+1))))

一个实现：

num =input("Input n:")
sum = 0

for i in range(1,int(num)+1):
    sum=  sum+ i
    
print("sum="+str(sum)+"")