Internal Server error: using python script with sqlite using module mod_wsgi in apache

This is my code example.

import sqlite3

def application(environ, start_response):

 output = "<center><p> LOG</p>"

 db = sqlite3.connect('/root/example.db')
 db.row_factory = sqlite3.Row
 cursor = db.cursor()
 cursor.execute('''SELECT id, message,date FROM table''')
 for row in cursor:
  print('{0} : {1}, {2}'.format(row['id'], row['message'], row['date']))
 db.close()

start_response('200 OK', [('Content-Type', 'text/html; charset=utf-8')])
return output

I get Internal Server Error.

How would solve the problem?