input: Write a function to convert a given SQL statement into a Python Pandas DataFrame. The function should take a SQL query string and a database connection object as input parameters, execute the query, and return the resulting DataFrame. If the input query is "SELECT * FROM book;" and the connection object is named `conn`, the function should return a DataFrame containing all columns and rows from the `book` table.
  assert convert_sql_to_df("SELECT * FROM book;", conn).equals(pd.read_sql_query("SELECT * FROM book;", conn)) == True
output: def convert_sql_to_df(query, conn):
      return pd.read_sql_query(query, conn)