how to plot a bar using matplotlib

1import matplotlib.pyplot as plt  
2  
3   
4# creating the dataset 
5data = {'C':20, 'C++':15, 'Java':30,  
6        'Python':35} 
7courses = list(data.keys()) 
8values = list(data.values()) 
9   
10
11fig = plt.figure(figsize = (5, 5)) 
12  
13# creating the bar plot 
14plt.bar(courses, values, color ='green',  
15        width = 0.4) 
16  
17plt.xlabel("Courses offered") 
18plt.ylabel("No. of students enrolled") 
19plt.title("Students enrolled in different courses") 
20plt.show()