birthday_paradox_plotted_nicely.py

import matplotlib.pyplot as plt

df_sample_grouped = df_sample.groupby(['birthday']).size()
n_unique_dates = len(df_sample_grouped.index.unique())

fig = plt.figure(figsize=(n_unique_dates/5, n_unique_dates/10))

ax = df_sample_grouped.plot.bar(x="birthday", y="n_pets", color='blue')
ax.set_xticklabels(labels=df_sample_grouped.index, rotation=70, rotation_mode="anchor", ha="right");
ax.legend(labels=['n_pets']);

plt.tight_layout()