1
Set the matplotlib backend to Agg before importing pyplot
3
Plot one line per product on the same axes using plt.plot called multiple times or a pivot plot
4
Each line must have a label so the legend works
5
Add a legend using plt.legend
6
Add gridlines using plt.grid(True) to make the chart readable
7
Add a title and axis labels
8
Save the chart as multi_line_chart.png