Python uses insert to add new elements to the end of the list

We know how to use -1 To specify the subscript ：

alist=[1,2,3]
alist.insert(-1,4)
print(alist)

Output ：

[1, 2, 4, 3]

This will turn 4 Insert into 3 The location of , And then put 3 Move backward ,4 Second to last on the new list .

You need to use a subscript that is greater than or equal to the length of the list ：

alist=[1,2,3]
alist.insert(len(alist),4)
alist.insert(10,5)
print(alist)

Output ：

[1, 2, 3, 4, 5]

len(alist) More than the alist The maximum subscript of , as long as insert The first parameter of is that the values exceeding the maximum subscript are inserted at the end of the list by default .