问：python语法不太熟，不知这样写对不对

运行程序的时候最后输入end总是报错，说end没有定义，但我自己并看不出问题

 

n = str(input("Enter a number, end with 'end':"))

s = []

while n.lower() != "end":

    s.append(int(n))

    n = str(input("Enter a number, end with 'end':"))

 

s.sort()

even_number = 0

odd_number = 0

for i in s:

    if s[i]%2 == 0:

        even_number+=1

    else:

        odd_number+=1

 

print('the smallest value is ',s[0],'the largest value is ',s[-1])

print('the number of even number is ',even_number,'the number of odd number is ',odd_number)

Sum = 0

for i in s:

    Sum +=s[i]

    print(Sum)

答：
python2的help:

 

Help on built-in function input in module builtin:

 

input(...)

input([prompt]) -> value

 

Equivalent to eval(raw_input(prompt)).

把输入的字符串当成表达式来计算，因此end会解释为一个变量。但是因为end在代码中未定义，所以出错：

NameError: name 'end' is not defined

 

解决办法： 改用 raw_input()