You can add a legend in Matplotlib with the following code. If you want to learn Python then I will highly recommend you to read This Book.

Add legend in Matplotlib
from matplotlib import pyplot as plt x = [1,2,3,4,5] y = [5,10,15,20,25] z = [10,20,30,40,50] plt.title("Numbers and Products") plt.xlabel("Numbers") plt.ylabel("Products") plt.plot(x,y,label="Between X and Y") plt.plot(x,z,label="Between X and Z") plt.legend() plt.show()

People are also reading:
What is Computer Vision? Examples, Applications, Techniques
Top 10 Computer Vision Books with Python
Books for Machine Learning (ML)