String concatenation

Foreword:

Author: The Children of God Are Singing

Hi, my name is Zhi

Introduction

In python, strings can be concatenated by + sign, join method , and % sign

But in python, use plus sign + to connect strings as little as possible, because String objects are fixed-length objects. Once created, the length cannot be changed. If you use + sign to connect two strings, it will open up a new section of memory with the total length of the original length, and then memcpy the two strings into it.If you want to connect N String objects, you need to perform N-1 memory allocations and copies.The official recommendation is to use the join method of strings. This method is very effective for connecting elements in a list or tuple. It will first count the lengths of all elements, apply for memory, and then copy.

If you want to splicing characters in a loop, I use string formatting % operator display

Use

sd = "God" + "child" + "are singing"print(sd)sb_list = ["God", "Kids", "are singing"]print(''.join(sb_list))sb_replace = '%s%s%s' %("God", "children", "all singing")print(sb_replace)sb_replace = "{}{}{}".format("God", "child", "bothSinging")print(sb_replace)

References

Three common and most efficient Python string concatenation methods

Several ways to concatenate strings in Python

python lists combined into strings

My csdn blog: https://blog.csdn.net/weixin_46654114

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