old_contents: from flask import (
      Markup,
      abort,
      flash,
      redirect,
      render_template,
      request,
      session,
      url_for,
  )
  from flask_login import current_user
  
  from app import login_manager
  from app.main import main
  from app.main.forms import LoginForm
  from app.models.user import InvitedUser, User
  
  
  @main.route('/sign-in', methods=(['GET', 'POST']))
  def sign_in():
      if current_user and current_user.is_authenticated:
          return redirect(url_for('main.show_accounts_or_dashboard'))
  
      form = LoginForm()
  
      if form.validate_on_submit():
  
          user = User.from_email_address_and_password_or_none(
              form.email_address.data, form.password.data
          )
  
          if user and user.state == 'pending':
              return redirect(url_for('main.resend_email_verification'))
  
          if user and session.get('invited_user'):
              invited_user = InvitedUser.from_session()
              if user.email_address.lower() != invited_user.email_address.lower():
                  flash("You can't accept an invite for another person.")
                  session.pop('invited_user', None)
                  abort(403)
              else:
                  invited_user.accept_invite()
          if user and user.sign_in():
              if user.sms_auth:
                  return redirect(url_for('.two_factor', next=request.args.get('next')))
              if user.email_auth:
                  return redirect(url_for('.two_factor_email_sent'))
  
          # Vague error message for login in case of user not known, locked, inactive or password not verified
          flash(Markup(
              (
                  "The email address or password you entered is incorrect."
                  " <a href={password_reset}>Forgot your password</a>?"
              ).format(password_reset=url_for('.forgot_password'))
          ))
  
      other_device = current_user.logged_in_elsewhere()
      return render_template(
          'views/signin.html',
          form=form,
          again=bool(request.args.get('next')),
          other_device=other_device
      )
  
  
  @login_manager.unauthorized_handler
  def sign_in_again():
      return redirect(
          url_for('main.sign_in', next=request.path)
      )
  
new_contents: from flask import (
      Markup,
      abort,
      flash,
      redirect,
      render_template,
      request,
      session,
      url_for,
  )
  from flask_login import current_user
  
  from app import login_manager
  from app.main import main
  from app.main.forms import LoginForm
  from app.models.user import InvitedUser, User
  
  
  @main.route('/sign-in', methods=(['GET', 'POST']))
  def sign_in():
      if current_user and current_user.is_authenticated:
          return redirect(url_for('main.show_accounts_or_dashboard'))
  
      form = LoginForm()
  
      if form.validate_on_submit():
  
          user = User.from_email_address_and_password_or_none(
              form.email_address.data, form.password.data
          )
  
          if user and user.state == 'pending':
              return redirect(url_for('main.resend_email_verification'))
  
          if user and session.get('invited_user'):
              invited_user = InvitedUser.from_session()
              if user.email_address.lower() != invited_user.email_address.lower():
                  flash("You cannot accept an invite for another person.")
                  session.pop('invited_user', None)
                  abort(403)
              else:
                  invited_user.accept_invite()
          if user and user.sign_in():
              if user.sms_auth:
                  return redirect(url_for('.two_factor', next=request.args.get('next')))
              if user.email_auth:
                  return redirect(url_for('.two_factor_email_sent'))
  
          # Vague error message for login in case of user not known, locked, inactive or password not verified
          flash(Markup(
              (
                  "The email address or password you entered is incorrect."
                  " <a href={password_reset}>Forgot your password</a>?"
              ).format(password_reset=url_for('.forgot_password'))
          ))
  
      other_device = current_user.logged_in_elsewhere()
      return render_template(
          'views/signin.html',
          form=form,
          again=bool(request.args.get('next')),
          other_device=other_device
      )
  
  
  @login_manager.unauthorized_handler
  def sign_in_again():
      return redirect(
          url_for('main.sign_in', next=request.path)
      )
  
subject: Replace can't with cannot