Quickest inline d3.js in Jupyter

Everyone has their own way to use d3.js in Jupyter. Here is the shortest and most concise I've been able to put together.

Step 1

Download d3.js and put it into the directory ~/.jupyter/custom

Step 2

Create a file ~/.jupyter/custom/custom.js and put the following into that file (note there is no ".js" in the quoted filepath):
require.config({paths:{d3:"/custom/d3.v5.min"}})

Step 3

In a Jupyter cell:

from IPython.core.display import display, Javascript
display(Javascript('''require(['d3'], function(d3) {
var svg = d3.select(element.get(0)).append('svg').attr('width',600).attr('height',200)
svg.append('circle').attr('cx',30).attr('cy',30).attr('r',20)
})'''))