TIMEZONES = tuple(zip(pytz.all_timezones, pytz.all_timezones))

    time_zone = models.CharField(max_length=100, blank=True, null=True, choices=TIMEZONES)

class Lesson(models.Model):
    user = models.ForeignKey(User, null=True, default=None, related_name='lessons', on_delete=models.CASCADE)
    lesson_instrument = models.CharField(max_length=255, choices=instrument_list, blank=True)
    lesson_level = models.CharField(max_length=255, choices=level_list, blank=True)
    lesson_length = models.CharField(max_length=255, choices=length_list, blank=True)
    lesson_datetime = models.DateTimeField(null=True, blank=True)
    lesson_weekly = models.BooleanField(default=False, blank=True)

def new_lesson(request):
    if request.method == 'POST':
        form = LessonForm(request.POST)

        if form.is_valid():
            lessons = form.save(commit=False)
            lessons.user = request.user
            lessons.save()
            messages.success(request,'Lesson successfully created')
            return redirect('/teacher/schedule')

        else:
            messages.error(request, 'Information entered was invalid')

    else:
        form = LessonForm()

    form = LessonForm()
    lessons = Lesson.objects.filter(user=request.user)
    context = {'form' : form, 'lessons': lessons}
    return render(request, 'teacher/new_lesson.html', context)

def student_sign_up(request):
    form = StudentSignUpForm(request.POST)

    if request.method == 'POST':
        form = StudentSignUpForm(request.POST)

        if form.is_valid():
            user = form.save()
            login(request, user)
            return redirect('/student/dashboard')

        else:
            messages.error(request, 'Make sure all your information is valid')

    else:
        form = StudentSignUpForm()

    context = {'form' : form}
    return render(request, 'accounts/student_sign_up.html', context)