I'm now going to give you a big assignment to push your learning a bit further. One way to speed up your education is to periodically pick something seemingly impossible and sit down to solve it for a few hours. Even if you completely fail at it, the act of trying pushes your knowledge past where you thought it could go. Sometimes though you figure out that you actually know more than you thought and you build new confidence. Doing this also gets you out of a "training rut" where you just do the same exercises over and over yet feel like you're never improving.

I've found a reasonably complex regular expression for matching IP addresses. It has most of the symbols you already know, and some that you don't know. Here's the regex you'll be working with:

\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b

What you will do is this:

• Write a corpus text file with about 5 IP addresses and 5 dates in it.
• Make sure this regex matches those 5 IP address and not the dates. Feel free to copy-paste the original regex to make sure you've got it right.
• Start a copy of the regex and rewrite it in verbose form the way you have been. Remember to put a blank line to start verbose mode, and then end it with a blank line.
• Any symbols you don't know you should look up in the Python re library documentation.
• As you rewrite it into verbose form, keep running regetron to make sure that the two regex continue to match what they used to match. Think of this as the same as running your unit tests.
• When you're done, write a single paragraph explaining how this regex works.