The bass on this song is absolutely fantastic.
This song starts as just some single notes and sustains, until it goes into a bunch of quick triplets, and starts jumping all across the fretboard.
The verses to this song are precisely that as well, you're constantly moving around the fretboard playing hammer-ons, pull-offs even some quick 2-note bass chords at some points.
The choruses (and there are alot of these, its a Clash song, what do you expect?), has you playing those rapid triplets again all over the place, and the choruses repeat often throughout the end of the song. At the last few choruses, however, you get to rest a bit and play some single notes and sustains until the outro where you jump all across the frets with single notes and the song ends.
Overall, this is a fantastic bass song with lots of movement and extremely fun triplets, and I would recommend this is you're mainly a bassist.