Create pandas.DataFrame , you can use seaborn.jointplot to plot the joint probability.

You can play around with the kind parameter to get the plot you desire.

import random
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
samples = 100
x = random.choices(population = [0.25, 0.75], weights = [25, 75], k = samples)
y = random.choices(population = [0.4, 0.6], weights = [4, 6], k = samples)
df = pd.DataFrame({'x': x, 'y': y})
sns.jointplot(data = df, x = 'x', y = 'y', kind = 'kde', xlim = (0, 1), ylim = (0, 1))
plt.show()