old_contents: from flask import render_template
  from flask_app import app
  
  @app.route('/')
  def index():
      return render_template('index.html')
  
  
new_contents: # -*- coding: utf-8 -*-
  import datetime
  from hashlib import sha256
  from time import gmtime, strftime
  
  import sqlalchemy
  from flask import render_template, redirect, url_for
  from flask_app import app, db_connection, dbTables
  from forms import RegisterForm
  
  
  @app.route('/', methods=('GET', 'POST'))
  def index():
      return render_template('index.html', title=u"Главная")
  
  @app.route('/success', methods=('GET', 'POST'))
  def success():
      return render_template('success.html', title=u"Регистрация завершена!")
  
  @app.route('/sign-up', methods=('GET', 'POST'))
  def sign_up():
      form = RegisterForm()
      if form.validate_on_submit():
          # new catalog for user
          catalog_name = str(form.data['login'] + "_main")
          new_dir = dbTables.Catalog(catalog_name)
          db_connection.session.add(new_dir)
          db_connection.session.commit()
          # new filespace for user
          fs_name = str(form.data['login'] + "_fs")
          new_fs = dbTables.FileSpace(fs_name, new_dir)
          db_connection.session.add(new_fs)
          db_connection.session.commit()
          fs = db_connection.session.execute(sqlalchemy.select([dbTables.FileSpace]).where(dbTables.FileSpace.storage_name == fs_name))
          fs = fs.fetchone()
          time_is = datetime.datetime.strptime(strftime("%d.%m.%Y", gmtime()), "%d.%m.%Y").date()
          time_is = time_is + datetime.timedelta(days=365)
          date_max = time_is.strftime("%d.%m.%Y")
          id_new = db_connection.session.execute(sqlalchemy.func.count(dbTables.Users.id)).fetchone()[0] + 1
          password_hash = str(sha256(form.data['password']+str(id_new)).hexdigest())
          # create new user
          new_user = dbTables.Users(form.data['login'], form.data['fullname'], password_hash, form.data['email'], date_max, 1, 2, fs.id)
          db_connection.session.add(new_user)
          db_connection.session.commit()
          return redirect(url_for('success'))
      return render_template('sign-up.html', title=u"Регистрация", form=form)
  
  @app.route('/sign-in', methods=('GET', 'POST'))
  def sign_in():
      return render_template('sign-in.html', title=u"Аутентификация")
  
  @app.route('/forgot-password', methods=('GET', 'POST'))
  def forgot_password():
      return render_template('forgot-password.html', title=u"Восстановление доступа")
subject: Add routes for other pages