old_contents: # -*- coding: utf-8 -*-
  from flask import render_template, request, jsonify
  from . import main
  
  
  @main.app_errorhandler(413)
  def request_entity_too_large(e):
    '''redirect to create item form if a user tries to upload
    an image bigger than 3MB'''
    return render_template('413.html'), 413
  
  
  @main.app_errorhandler(404)
  def page_not_found(e):
    if request.accept_mimetypes.accept_json and \
        not request.accept_mimetypes.accept_html:
      response = jsonify({'error': 'not found'})
      response.status_code = 404
      return response
    return render_template('404.html'), 404
  
  
  @main.app_errorhandler(500)
  def internal_server_error(e):
    if request.accept_mimetypes.accept_json and \
        not request.accept_mimetypes.accept_html:
      response = jsonify({'error': 'internal server error'})
      response.status_code = 500
      return response
    return render_template('500.html'), 500
new_contents: # -*- coding: utf-8 -*-
  from flask import render_template, request, jsonify
  from . import main
  # pylint: disable=W0613
  
  @main.app_errorhandler(413)
  def request_entity_too_large(e):
    '''redirect to create item form if a user tries to upload
    an image bigger than 3MB'''
    return render_template('413.html'), 413
  
  
  @main.app_errorhandler(404)
  def page_not_found(e):
    if request.accept_mimetypes.accept_json and \
        not request.accept_mimetypes.accept_html:
      response = jsonify({'error': 'not found'})
      response.status_code = 404
      return response
    return render_template('404.html'), 404
  
  
  @main.app_errorhandler(500)
  def internal_server_error(e):
    if request.accept_mimetypes.accept_json and \
        not request.accept_mimetypes.accept_html:
      response = jsonify({'error': 'internal server error'})
      response.status_code = 500
      return response
    return render_template('500.html'), 500
subject: disable pylint warning, related to #15