如果没有正则表达式的python中特定单词没有空格，如何在前后添加空格

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"

目前我正在用空格替换学校单词，如下所示

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

但是，由于上面的替换，它正在添加另一个空格，尽管有一个空格，这意味着我得到如下输出。 如果没有空间，有没有办法只添加空间。

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

我期待如下输出：处理这种情况的最佳方法，没有正则表达式。

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

注意：请忽略区分大小写

Answer 1

没有正则表达式

我会将 2 个空格的替换添加到一个.replace(" ", " ")和一个strip()中，以防您将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()

使用正则表达式

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)