code: def as_crispy_field(field, template_pack=TEMPLATE_PACK, label_class="", field_class=""):
      
      if not isinstance(field, forms.BoundField) and settings.DEBUG:
          raise CrispyError('|as_crispy_field got passed an invalid or inexistent field')
  
      attributes = {
          'field': field,
          'form_show_errors': True,
          'form_show_labels': True,
          'label_class': label_class,
          'field_class': field_class,
      }
      helper = getattr(field.form, 'helper', None)
  
      template_path = None
      if helper is not None:
          attributes.update(helper.get_attributes(template_pack))
          template_path = helper.field_template
      if not template_path:
          template_path = '%s/field.html' % template_pack
      template = get_template(template_path)
  
      c = Context(attributes).flatten()
      return template.render(c)
docs: Renders a form field like a django-crispy-forms field::
  
          {% load crispy_forms_tags %}
          {{ form.field|as_crispy_field }}
  
      or::
  
          {{ form.field|as_crispy_field:"bootstrap" }}