A few months ago I was looking for a similar solution but couldn't find one that handles empty cells very well. I ended up writing my own program[0] that is specific to my files' layout.
This library works perfectly and could've saved me a lot of time! Looking at some of the source code, we used similar logic to parse the tables. Pretty neat!
It depends on the model. For my XPS 15 with the bigger battery I can get up to 10 hours working on Python dev and checking out docs. But only when disabling the discrete Nvidia card, which is relatively straightforward[0] to do after having suffered setting up bumblebee.