Jupyter notebook tricks

 1. Merge multiple Jupyter Notebook cells into one

a. Let imagine that you have written thousands line of codes. And suddenly, you want to run the entire cells all over again with just one or two values changed.

Guess what? You will need to scroll up -> change the value -> run the notebook time and time again. The bad thing here is that you need to wait for one loop to finish before manually scrolling up and change the value. 

SUCKS!

So here let's put all the code in a loop by after merging all the cells into one using Shift + M.