A data engineer has a Python variable named table_name that they intend to incorporate into a SQL query in order to dynamically reference a table. Their goal is to construct a Python code block capable of executing the SQL query which selects the columns customer_id and spend from the specified table referenced by table_name. They currently possess the following incomplete code block: ___(f"SELECT customer_id, spend FROM {table_name}"). What keyword or function should be used to fill in the blank to successfully complete this task?