input: Write a function to create a command-line application in Python that stores customer data and allows customers to query by customer name. The function should read command-line arguments for the customer name and print the customer data if found. If the command-line arguments are invalid, print an error message.
  
  import sys 
    
  def print_customer_data(name): 
      # Code for searching customer data by customer name and 
      # printing results 
      ...
  
  # Main function for the customer search application
  if __name__=="__main__": 
      # Get command line arguments 
      args = sys.argv 
      
      if len(args) == 2: 
          name = args[1]
          print_customer_data(name) 
      else: 
          print("Invalid arguments, please specify a customer name.")
  
  assert print_customer_data("John Doe")==None 
  assert print_customer_data("Jane Smith")==None 
  assert print_customer_data("Invalid Customer")==None 
  assert len(sys.argv) == 0, "No arguments should not throw error"
  assert len(sys.argv) == 1, "Single argument should not throw error"
output: def print_customer_data(name): 
      customers = {
          "John Doe": "Customer ID: 123, Address: 123 Main St",
          "Jane Smith": "Customer ID: 456, Address: 456 Elm St"
      }
      if name in customers:
          print(customers[name])
      else:
          print("Customer not found.")