input: 
  def sql_to_dataframe(sql_query: str, connection: str) -> pd.DataFrame:
      """Convert a given SQL statement into a Pandas DataFrame.
      >>> sql_to_dataframe("SELECT * FROM book;", "connection_string")
      <class 'pandas.core.frame.DataFrame'>
      """
  
output:     
      import pandas as pd
      import sqlite3
  
      conn = sqlite3.connect(connection)
      df = pd.read_sql_query(sql_query, conn)
      conn.close()
      return df
  