如果沒有正則表達式的python中特定單詞沒有空格，如何在前后添加空格

Question

我有一個像下面這樣的字符串。

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

目前我正在用空格替換學校單詞，如下所示

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

但是，由於上面的替換，它正在添加另一個空格，盡管有一個空格，這意味着我得到如下輸出。 如果沒有空間，有沒有辦法只添加空間。

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

我期待如下輸出：處理這種情況的最佳方法，沒有正則表達式。

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

注意：請忽略區分大小寫

Answer 1

沒有正則表達式

我會將 2 個空格的替換添加到一個.replace(" ", " ")和一個strip()中，以防您將單詞作為最后一個單詞的第一個

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

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

使用正則表達式

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)