Python – Two different bar charts next to each other

March 30, 2023

I am using matplotlib to analyze my data. For this I created a dataframe with following structure:

merge.set_index('index', inplace=True)
print(merge)
            username  mentioned_user
index       
matthiashauer   73    10
derya_tn        67    5
renatekuenast   36    9
ralf_stegner    35    73
mgrossebroemer  33    12
... ... ...
katrinhelling   1     1
gydej           1     2
martingassner   1     2
daniludwigmdb   1     3
philipphartewig 1     1

Now I want to plot two bar charts in one row. One the left side, there should be the bar chart with "username" column (ascending, first 10 biggest values) and on the right side there should be the the bar chart with the "mentioned_user" column (ascending, first 10 biggest values). As the values of the columns are different, the y-axis label for each bar chart has to be different.
Here is the plot that I have so far:

merges = merge[:30]

font_color = '#525252'
hfont = {'fontname':'Calibri'}
facecolor = '#eaeaf2'
color_red = '#fd625e'
color_blue = '#01b8aa'
index = merges.index
column0 = merges['username']
column1 = merges['mentioned_user']
title0 = 'Spreading Hate'
title1 = 'Receiving Hate'

fig, axes = plt.subplots(figsize=(10,5), facecolor=facecolor, ncols=2, sharey=True)
fig.tight_layout()

axes[0].barh(index, column0, align='center', color=color_red, zorder=10)
axes[0].set_title(title0, fontsize=18, pad=15, color=color_red, **hfont)
axes[1].barh(index, column1, align='center', color=color_blue, zorder=10)
axes[1].set_title(title1, fontsize=18, pad=15, color=color_blue, **hfont)

# To show data from highest to lowest
plt.gca().invert_yaxis()

axes[0].set(yticks=merges.index, yticklabels=merges.index)
axes[0].yaxis.tick_left()
axes[1].yaxis.tick_right()
axes[0].tick_params(axis='y', colors='black') # tick color

for label in (axes[0].get_xticklabels() + axes[0].get_yticklabels()):
    label.set(fontsize=13, color=font_color, **hfont)
for label in (axes[1].get_xticklabels() + axes[1].get_yticklabels()):
    label.set(fontsize=13, color=font_color, **hfont)

plt.subplots_adjust(wspace=0, top=0.85, bottom=0.1, left=0.18, right=0.95)

filename = 'politicians_spread_vs_receive_hate'
plt.savefig(filename+'.png', facecolor=facecolor)

For the left plot, I get the correct order and y-axis labels. However for the right plot, I would need to order the data as well and would also need another y-axis label on the right side.

How can I do this?

Thanks in advance!

>Solution :

However for the right plot, I would need to order the data as well …

Then you should re-order the merges dataframe by mentioned_user before drawing the bar on the second axis.

… and would also need another y-axis label on the right side.

For that, you’ll need to remove sharey=True from the plt.subplots() call and move the ticks of the second axis to the right with ax.yaxis.tick_right()

Here is a minimal example with fake data

fig, (ax1, ax2) = plt.subplots(figsize=(10, 5), ncols=2)

merges = merges.sort_values("username")
ax1.barh(merges.index, merges["username"], align='center')
ax1.set_title("Spreading Hate")

merges = merges.sort_values("mentioned_user")
ax2.barh(merges.index, merges["mentioned_user"], align='center')
ax2.set_title("Receiving Hate")
ax2.yaxis.tick_right()

plt.subplots_adjust(wspace=0, top=0.85, bottom=0.1, left=0.18, right=0.95)