Adding extra space along the x-axis in matplotlib bar graph

Question

I'm using matplotlib to draw a bar chart with 3 bars. I want to add some extra space along the x-axis (so that the x-axis line is drawn longer).

Below is what I have:

import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline

dt = [1,3,2]
plt.figure()
xvals = range(len(dt))
plt.bar(xvals, dt, width=0.5)
plt.tick_params(bottom=False)
plt.xticks(xvals, ['a','b','c'])
plt.yticks(range(0,4), [0,1,2,3])

plt.gca().spines['top'].set_visible(False)
plt.gca().spines['right'].set_visible(False)

plt.show()

This code produces:

I simply want (note the elongated x-axis):

Answer 1

Change the limits of the x-axis using xlim()

for ex:

plt.xlim(-0.5,3.5)  # adjust as necessary

Answer 2

Just add the following limits. Yo can use None as the left hand limit to let the plot choose the limit as the default value. Since the x-values are 0, 1, 2 and now you add the right hand side limit as 3, you will have an extended axis. Replace 3 by whatever value you want.

plt.xlim(None, 3)