一个python小bug，希望帮忙看下

Question

执行代码

countsum = [163, 211, 121, 46, 11]
sumrate= countsum
for i in sumrate:
    i /= total
    print(i)
print("sum rate is "+str(sumrate))

得到结果
0.29528985507246375
0.3822463768115942
0.21920289855072464
0.08333333333333333
0.019927536231884056
sum rate is [163, 211, 121, 46, 11]
python初学，不太懂这是什么原理，怎么改，谢谢

Answer 1

这是显而易见的，迭代器变量i并不直接引用到数组中，修改i不会修改数组的元素。

你需要这么写

# encoding: utf-8

total = 552.0
countsum = [163, 211, 121, 46, 11]
sumrate = list(map(lambda i : i / total, countsum))
print("sum rate is " + str(sumrate))

结果：
sum rate is [0.29528985507246375, 0.3822463768115942, 0.21920289855072464, 0.08333333333333333, 0.019927536231884056]