input: from typing import List, Dict
  
  def print_customer_data(customer_db: Dict[str, str], name: str) -> None:
      """ Function to search customer data by customer name and print the results.
      If the customer is found in the database, it prints the customer's details.
      If the customer is not found, it prints "Customer not found."
      
      >>> print_customer_data({"Alice": "123 Main St", "Bob": "456 Elm St"}, "Alice")
      Alice, 123 Main St
      >>> print_customer_data({"Alice": "123 Main St", "Bob": "456 Elm St"}, "Charlie")
      Customer not found.
      """
      for customer, address in customer_db.items():
          if customer == name:
              print(f"{customer}, {address}")
              return
      print("Customer not found.")
output:     for customer, address in customer_db.items():
          if customer == name:
              print(f"{customer}, {address}")
              return
      print("Customer not found.")