text: from flask import render_template, request, jsonify
  from . import errors
  
  
  @errors.app_errorhandler(404)
  def page_not_found(e):
      if (
          request.accept_mimetypes.accept_json and
          not request.accept_mimetypes.accept_html
      ):
          return jsonify({'error': 'not found'}), 404
      return render_template('404.html'), 404
  
  
  @errors.app_errorhandler(500)
  def internal_server_error(e):
      if (
          request.accept_mimetypes.accept_json and
          not request.accept_mimetypes.accept_html
      ):
          return jsonify({'error': 'internal server error'}), 500
      return render_template('500.html'), 500
  
  
  @errors.app_errorhandler(403)
  def forbidden(e):
      if (
          request.accept_mimetypes.accept_json and
          not request.accept_mimetypes.accept_html
      ):
          return jsonify({'error': 'forbidden'}), 403
      return render_template('403.html'), 403
  