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()
