+ =在python 3中表示什么？

Question

例如，在一起添加列表时：

list = [1,2,3,4,5]

list_sum = 0
for x in list:
   list_sum += x

Answer 1

list_sum += x表示将list_sum变量的内容添加到变量x的内容中，然后再将结果存储到list_sum变量。

代码说明：

list_sum = 0     # At first, 0 is assigned to the `list_sum` variable .
for x in list:   # iterating over the contents which are present inside the variable `list`
list_sum += x    # list_sum = 0+1 . After the first iteration, value 1 is stored to list_sum variable. Likewise it sums up the values present in  the list and then assign it back to list_sum variable. Atlast `list_sum` contains the sum of all the values present inside the given list.

Answer 2

list_sum = list_sum + x

的shorthand

for x in list:将遍历list中的每个元素，将值分配给临时变量x

查看以下重复项：

Duplicate 1并且不完全重复 another example of how it works

Answer 3

缩短了用于任何语言list_sum += x => list_sum = list_sum + x的操作 也可以分别是“ - =”，“* =”和“/ =”。