title: How can I set CSS class for django-filter generated elements?
body: <p>I am using django-filter(little library for django elements filtering). And I want to know how can I add some CSS classes to that generated HTML elements. Here is code for filters.py. Thank you from Armenia nice person :)</p>
  <pre><code>class Filter(django_filters.FilterSet):
      CHOICES = (
          ('ascending', 'По дате (А-Я)'),
          ('descending', 'По дате (Я-А)'),
      )
      CHOICES2 = (
          ('price_low', 'По цене по возрастанию'),
          ('price_high', 'По цене по убыванию'),
      )
  
  orderDate = django_filters.ChoiceFilter(choices=CHOICES, method='filter_by_date', label='')
  orderPrice = django_filters.ChoiceFilter(choices=CHOICES2, method='filter_by_price', label='')
  category = django_filters.ModelChoiceFilter(field_name='category', queryset=Category.objects.all())
  
  class Meta:
      model = Product
      fields = {
          'price': ['gt', 'lt'],
          'category': [],
      }
  
  def filter_by_date(self, queryset, name, value):
      expr = 'date' if value == 'ascending' else '-date'
      return queryset.order_by(expr)
  
  def filter_by_price(self, queryset, name, value):
      expr = 'price' if value == 'price_low' else '-price'
      return queryset.order_by(expr)
  </code></pre>