Matplotlib code

plt.figure(figsize=(12,10))

plt.subplot(2, 1, 1)
transactions.isnull().sum().plot(kind="bar", title="Transactions")

plt.subplot(2,2,4)
new_customers.isnull().sum().plot(kind="bar", title="New Customers")

plt.subplot(2,2,3)
customer_demographics.isnull().sum().plot(kind="bar", title="Customer Demographics")

plt.subplots_adjust(top=0.88)
plt.suptitle("Incomplete Values per Sheet", fontsize=16)
plt.tight_layout()
plt.show()