additional characters

• At the start of this article , i said that in python , a string is an immutable sequence of characters . the last few lines of the previous example demonstrate this , as i first create a string and then modify it by adding additional characters
  我在本文开头说过，在python中，字符串是不变的字符序列,上例中的最后几行说明了这一点，我首先创建一个字符串，然后通过添加其他字符串对它进行修改。