This example visualizes the average energy price by country, computed from a CSV file of daily energy records. The code aggregates energy prices per country, calculates each country’s mean, and renders a bar chart using SVG. It employs D3 v7’s `scaleBand` for the x-axis and `scaleLinear` for the y-axis, along with `d3.csv` to load the data and `d3.axisBottom` and `d3.axisLeft` for the axes.