How it works...

So, this is how the explanation goes:

• plt.plot([1.5, 3.0]) plots a line graph connecting two points (0, 1.5) and (1.0, 3.0).
• The plot command expects two arguments (Python list, NumPy array or pandas DataFrame) for the x and y axis respectively.
• If only one argument is passed, it takes it as y axis co-ordinates and for x axis co-ordinates it takes the length of the argument provided.
• In this example, we are passing only one list of two points, which will be taken as y axis coordinates.
• For the x axis, it takes the default values in the range of 0 to 1, since the length of the list [1.5, 3.0] is 2.
• If we had three coordinates in the list for y, then for x, it would take the range of 0 to 2.
• You should see the graph like the one shown in step 6.
• plt.title("Interactive Plot"), prints the title on top of the graph as Interactive Plot.
• plt.xlabel("X-axis"), prints the x axis label as X-axis.
• plt.ylabel("Y-axis"), prints the y axis label as Y-axis.
• After executing preceding three statements, you should see the graph as shown in step 7.

If you are using Python shell, after executing each of the code statements, you should see the graph getting updated with title first, then the x axis label, and finally the y axis label.

If you are using Jupyter Notebook, you can see the output only after all the statements in a given cell are executed, so you have to put each of these three statements in separate cells and execute one after the other, to see the graph getting updated after each code statement.