如果python中没有regex的特定单词的空格，如何在前面或后面添加空格

Question

我有一个像下面这样的字符串。

txt1 = "Krish is a school boy and Mahesh is anotherschool boy, Gang is good schoolboy"

目前我正在更换学校带空格的单词

txt1.lower().replace("school"," school ")

但是，由于上面的替换，它添加了另一个空间，尽管有一个空间，这意味着我得到的输出如下所示。有没有一种方法，如果没有空间，那么只添加空间。

'krish is a  school  boy and mahesh is another school  boy, gang is good  school boy'

我期望输出如下:任何最好的方法来处理这种情况，没有regex。

'Krish is a school boy and Mahesh is another school boy, Gang is good school boy'

注意:请忽略大小写敏感性

Answer 1

不带regex

我会在一个.replace(" ", " ")和一个strip()中添加两个空格的替换，以防你的单词作为最后一个单词的第一个

txt1 = "Krish is a school boy and Mahesh is anotherschool boy, Gang is good schoolboy"
txt1 = txt1.lower().replace("school", " school ").replace("  ", " ").strip()

与正则表达式

import re
txt1 = "Krish is a school boy and Mahesh is anotherschool boy, Gang is good schoolboy"
txt1 = re.sub(r"school(S)", r"school 1", txt1)
txt1 = re.sub(r"(S)school", r"1 school", txt1)