Bar Graph not showing 0

Question

The y-axis of my bar graph isn't starting from 0. It is taking the minimum of the three values to be displayed as the starting point. I want it to go from zero to fifteen

data = {'Average Time of 1st Instance':average_value1, 'Average Time of 2nd Instance':average_value2, 'Average Time of 3rd Instance':average_value3}  
instances = list(data.keys())  
times = list(data.values())  
fig = plt.figure(figsize = (10, 5))
plt.bar(instances, times, color ='blue', width = 0.4)
plt.xlabel('Instance of ++HSS')
plt.ylabel('Time in Seconds')
plt.title('Time Taken to run the Three Instances of ++HSS')`  
plt.show()

This is the graph I'm getting:

Setting the y axis limits using plt.ylim(0, 15) is also not working

Data:
average_value1 = 8.88
average_value2 = 11.86
average_value3 = 11.36

Answer 1

The problem is that your average_value values are strings rather than numbers. If you change the line:

times = list(data.values())

to instead be:

times = [float(d) for d in data.values()]

to explicitly convert the values to floating point numbers you should get what you expect.

Alternatively, convert them when you create the dictionary, i.e.,

data = {
    'Average Time of 1st Instance': float(average_value1),
    'Average Time of 2nd Instance': float(average_value2),
    'Average Time of 3rd Instance': float(average_value3)
} 

Answer 2

Have you tried to add also the ticks values? Something on the line of this:

    yticks = np.linspace(0,15,3) 
    plt.yticks(yticks, yticks)

Answer 3

Your question is similar to How to set the axis limits . In particular I would use

ax = plt.gca()
ax.set_xlim([xmin, xmax])
ax.set_ylim([ymin, ymax])