Python merge list, append (), extend (), +, + =

The problem of list merging is involved in the actual application.

When you apply append (), the discovery list is appended to the list as an element, and the last query is followed by the Extend () method, and the following is the difference  1.append () appends a new element to the end of the list, which takes up only one index bit and adds 2.extend () appends a list to the end of the list, appending each element in the list to the existing list, adding 3.+ directly with the + sign appears with the same effect as the extend (), but actually generates a new list of the sum of the two lists, which can only be added to two listsThe 4.+= effect, like extend (), appends a new element to the original list, adding  The effect is as follows:

Python merge list, append (), extend (), +, + =