So, it looks like the CoinMarketCap has changed their site a bit and it breaks the coinmarketcap.py script I wrote back in July. Many thanks to cool007zqw for pointing this out by adding an issue on the repo.
On investigation it looks like CoinMarketCap changed the url to the page which the script was developed for.
The new page is as follows:
This does show the fragility of building scripts to pull pages from web sites. I do see that CoinMarketCap has an API over at https://coinmarketcap.com/api/ so that may be the way forward to build something more robust.