在标签和文本之间添加字符串

Question

我只想在字符串开头的（0或更多）标签后添加字符串。 即。

a = '\t\t\tHere is the next part of string.  More garbage.'

（插入Added String here.） 到

b = '\t\t\t Added String here. Here is the next part of string.  More garbage.'

最简单/最简单的方法是什么？

Answer 1

简单：

re.sub(r'^(\t*)', r'\1 Added String here. ', inputtext)

^插入符号匹配字符串的开头，\t一个制表符，其中应该有零个或多个（*）。括号捕获匹配的选项卡以便在替换字符串中使用，其中\1将它们再次插入到您需要添加的字符串前面。

演示：

>>> import re
>>> a = '\t\t\tHere is the next part of string.  More garbage.'
>>> re.sub(r'^(\t*)', r'\1 Added String here. ', a)
'\t\t\t Added String here. Here is the next part of string.  More garbage.'
>>> re.sub(r'^(\t*)', r'\1 Added String here. ', 'No leading tabs.')
' Added String here. No leading tabs.'