#183 Creating a boxplot using seaborn

import numpy as np
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import os
os.chdir(r'D:\projects\wordpress\ex184') 
os.getcwd()
url = "https://archive.ics.uci.edu/ml/machine-learning-databases/auto-mpg/auto-mpg.data"
df = pd.read_csv(url)
column_names = ['mpg', 'cylinders', 'displacement', 'horsepower', 'weight', 'acceleration', 'year', 'origin', 'name']
df = pd.read_csv(url, names= column_names, delim_whitespace=True)
print(df.head())
#Convert the horsepower and year data types to float and integer
df.loc[df.horsepower == '?', 'horsepower'] = np.nan
df['horsepower'] = pd.to_numeric(df['horsepower'])
df['full_date'] = pd.to_datetime(df.year, format='%y')
df['year'] = df['full_date'].dt.year
#Plot the average horsepower per year
sns.boxplot(data=df, x="cylinders", y="horsepower")
plt.savefig('ex184.jpg', dpi=300)