Adding dotted lines to Bar chart in Python

I need a bit of help with Python modules and code.

I want to create bar graph for the following data:

and the bar chart should look somewhat like this:

While it has been easy to plot bar chart and label it using plotly, I am unable to add the lines with text box and a box around second bar.

Can you please help me with it?

>Solution :

You can use a simple loop with plot and text:

df = pd.DataFrame({'data': [100, 60]}, index=['potential', 'expected'])

ax = df.plot.bar()

texts = ['this is line A', 'this is line B']

for i, v in enumerate(df['data']):
    print(i,v)
    ax.plot([i+0.25, ax.get_xlim()[-1]], [v, v],
            ls='--', c='k')
    ax.text(ax.get_xlim()[-1]+0.1, v, texts[i])

output:

For the rectangle, you need to compute some width around your bars:

import matplotlib.patches as patches
r = patches.Rectangle((1-0.3, 0), 0.6, 60*1.05,
                      lw=3, ls='--',
                      edgecolor='#ED7D31', facecolor='none'
                     )
ax.add_patch(r)

output:

Alternative for rectangle outside the axes:

import matplotlib.patches as patches
r = patches.Rectangle((1-0.3, -60*0.05), 0.6, 60*1.1,
                      lw=3, ls='--',
                      edgecolor='#ED7D31', facecolor='none',
                      clip_on=False
                     )
ax.add_patch(r)

output: