Python Matplotlib Bubble Chart

Let’s consider the below data. We would like to create a bubble chart using matplotlib where x-axis will be the Risk Value and y-axis will be the Financial Value. The size of the bubble would be determined by the Cost. Every bubble would represent a project.

Data is available here.

Python code…

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import random

#Importing Data
df = pd.read_csv(r'F:\Python\Sample Data for Bubble Chart.txt', sep='\t', 
                 low_memory=True, encoding='latin-1', error_bad_lines=False, 
                 thousands=',', header=0)

group = list(df['Department'].unique())

data = []
for i in group:
    data.append(df[df['Department']==i])

color=[]
for i in range(len(df['Department'].unique())):
    r = lambda: random.randint(0,255)
    color.append('#%02X%02X%02X' % (r(),r(),r()))
    
# Create plot
fig = plt.figure(figsize=(10,7), dpi=200)
ax = fig.add_subplot(1,1,1)
ax.spines['left'].set_visible(False)
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
ax.spines['bottom'].set_visible(False)

ax.xaxis.grid(b=False, which='major', color='gray', linestyle='--', alpha=0.5)
ax.yaxis.grid(b=False, which='major', color='gray', linestyle='--', alpha=0.5)

for d, c, g in zip(data, color, group):
    x=d['Risk Value']
    y=d['Financial Value']
    s=d['Cost']*5
    ax.scatter(x, y, alpha=0.7, c=c, edgecolors='k', s=s, label=g)
    
    for i, txt in enumerate(d['Project Name']):
        ax.annotate(txt, (list(x)[i], list(y)[i]), 
                    fontsize=7,
                    horizontalalignment='center',
                    verticalalignment='center')
        
plt.title("Risk Value, Financial Value vs Cost Ratio")
plt.xlabel("Risk Value")
plt.ylabel("Financial Value")
plt.legend(loc=2)
plt.show()