\0 doesn't work in re.sub(). way around?

Question

In Python,

re.sub('(ab)c', r'\1d', 'xxxabcxxx') 

gives me back 'xxxabdxxx'.

You would expect re.sub('(ab)c', r'\0d', 'xxxabcxxx') to return 'xxxabcdxxx'. That is, you'd expect it to work in a similar way to m.group(0).

However, this isn't supported. http://bugs.python.org/issue17426#msg184210

What is a simple way to achieve what re.sub('(ab)c', r'\0d', 'xxxabcxxx') should achieve, without the use of re.sub()?

Answer 1

Use \g<0>. You can also use \g<1>, etc. for other groups, but 0 is the entire match.

This is explained in the documentation: http://docs.python.org/2/library/re.html#re.sub