I'm terrible at regex apparently, it makes no sense to me...

I'd like an expression for matching a time, like 01:23:45 within a string.

I tried this

(r'(([0-9]*2)[:])*2([0-9]*2)

but it's not working. I need to be able to get the entire timestamp. Others I've tried have only found like 2 digits in it.

You have your repeaters wrong I'm afraid:

r'\d{2}:\d{2}:\d{2}'

The correct syntax is {n,m} for minimum and maximum digits, or {n} for an exact match. The \d character class is also easier to use that [0-9]; it means the same thing for regular (non-Unicode) matching.