def login_page(request):
    if request.user.is_authenticated():
        return redirect('/')
    if request.method == 'POST':
        form = LoginForm(request.POST)
        user = authenticate(username=form.data['login'], password=form.data['password'])
        if user is not None:
            login(request, user)
            return redirect('/')
        else:
            return redirect('/login?login_error')
    else:
        return render(request, 'login_form.html', {'login_error': 'login_error' in request.GET})