In [1]:
data = np.random.randint(5,10,8)

fig, ax = plt.subplots()

ax.axis('off')

n = 3
nx = len(data)

ax.bar(n,data[n], color='#aa3333')

ax.set_xlim(0,nx)
ax.set_ylim(0,int(data.max())+1)


plt.xkcd()
axkcd = ax.twinx()

axkcd.set_xlim(ax.get_xlim())
axkcd.set_ylim(ax.get_ylim())

axkcd.set_frame_on(True)
axkcd.patch.set_visible(False)
plt.setp(axkcd.spines.values(), visible=True)

axkcd.bar(np.arange(n), data[:n], color='#aaaaaa')
axkcd.bar(np.arange(n+1,nx), data[n+1:], color='#aaaaaa')
Out[1]:
<Container object of 4 artists>
In [1]: