[Tutor] Using Python and Regex

[Bill]

Hi,

I'm relatively new to Python and I'm trying to write a script to iterate 
through a series of text files in folder searching for some specific 
text and write it to a CSV.

I plan to use Regex to match the text and I have already identified the 
Regex to do this. I've also got as far as creating a CSV using python 
but, being new to this, I'm looking for some pointers on how to traverse 
through the folder and open each file in turn to check the content for 
matches using Regex.

Any advice would be gratefully received.

Regards

Bill