What is \1 here?

[Albert-Jan Roskam]

----- Original Message -----
> From: Ned Batchelder <ned at nedbatchelder.com>
> To: python-list at python.org
> Cc: 
> Sent: Tuesday, November 11, 2014 12:52 PM
> Subject: Re: What is \1 here?

<snip> 

 
> You need to learn how to find this stuff out for yourself. Ben Finney 
> even gave you a pointer to a helpful site for experimenting with 
> regexes: http://pythex.org/
 
Cool. I also like this one, which hardly anybody appears to use:

python C:\Python27\Tools\Scripts\redemo.py
 
The functionality is virtually the same.