Building a chart of gun law strictness v. gun death rates in Python...

gunchart.py

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
%matplotlib inline
#
# Read in the Brady Scores data, and extract the appropriate sheet into a DataFrame
#
workbook = pd.ExcelFile('Downloads/Brady-State-Scorecard-2014.xlsx')
dictionary = {}
for sheet_name in workbook.sheet_names:
    df = workbook.parse(sheet_name)
    dictionary[sheet_name] = df
scores = dictionary['scores rank']
#
# Read in the CDC data on gun-death rates
#
death_rate = pd.read_csv('Downloads/FIREARMS2016.csv', thousands=',')
#
# Merge the two dataframes
#
merged = scores.merge(death_rate, how='inner', left_on='ST', right_on='STATE')
#
# Plot the chart
#
fit = np.polyfit(merged['SCORE'], merged['RATE'], deg=1)
plt.figure(figsize=(10, 8))
plt.xlabel('Brady Center Score (higher is stricter)')
plt.ylabel('Guns Deaths per 100K Population')
plt.title('Gun Law Strictness vs. Rate of Gun Deaths')
plt.plot(merged['SCORE'], fit[0] * merged['SCORE'] + fit[1], color='red')
plt.scatter(merged['SCORE'], merged['RATE'], s=merged['DEATHS']/15.)
for i, txt in enumerate(merged['ST']):
    plt.annotate(txt, (merged['SCORE'].iat[i], merged['RATE'].iat[i]))
plt.show()

CDC data is at https://www.cdc.gov/nchs/pressroom/sosmap/firearm_mortality/FIREARMS2016.csv

Brady Score data is at http://crimadvisor.com/data/Brady-State-Scorecard-2014.xlsx