percentage stacked bar chart sns

# import libraries
import seaborn as sns
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches

# load dataset
tips = sns.load_dataset("tips")

# set the figure size
plt.figure(figsize=(14, 14))

# from raw value to percentage
total = tips.groupby('day')['total_bill'].sum().reset_index()
smoker = tips[tips.smoker=='Yes'].groupby('day')['total_bill'].sum().reset_index()
smoker['total_bill'] = [i / j * 100 for i,j in zip(smoker['total_bill'], total['total_bill'])]
total['total_bill'] = [i / j * 100 for i,j in zip(total['total_bill'], total['total_bill'])]

# bar chart 1 -> top bars (group of 'smoker=No')
bar1 = sns.barplot(x="day",  y="total_bill", data=total, color='darkblue')

# bar chart 2 -> bottom bars (group of 'smoker=Yes')
bar2 = sns.barplot(x="day", y="total_bill", data=smoker, color='lightblue')

# add legend
top_bar = mpatches.Patch(color='darkblue', label='smoker = No')
bottom_bar = mpatches.Patch(color='lightblue', label='smoker = Yes')
plt.legend(handles=[top_bar, bottom_bar])

# show the graph
plt.show()