input: Write a function to convert the given SQL query into a Python program. The function should connect to a database, execute the query, and print the results. The SQL query selects all columns from the "orders" table where the order date is in the year 2020. If the connection details are not provided, the function should raise an error.
  assert convert_sql_to_python("SELECT * FROM orders WHERE YEAR(order_date) = 2020")==None
  assert convert_sql_to_python("SELECT * FROM orders WHERE YEAR(order_date) = 2021")==None
  assert convert_sql_to_python("")==None
  assert convert_sql_to_python("INVALID SQL QUERY")==None
output: def convert_sql_to_python(query):
      if not query:
          raise ValueError("Query cannot be empty")
      if "SELECT * FROM orders WHERE YEAR(order_date) = 2020" not in query:
          raise ValueError("Invalid SQL query")
      import sqlite3
      conn = sqlite3.connect('example.db')
      cursor = conn.cursor()
      cursor.execute(query)
      results = cursor.fetchall()
      for row in results:
          print(row)
      conn.close()