  
          try:
              page = paginator.page(page_number)
          except InvalidPage as exc:
              error_format = _('Invalid page ({page_number}): {message}')
              raise NotFound(error_format.format(
                  page_number=page_number, message=six.text_type(exc)
              ))
  
          return page
 
</s> remove             raise exceptions.AuthenticationFailed('Invalid token')
 </s> add             raise exceptions.AuthenticationFailed(_("Invalid token")) </s> remove             msg = 'Invalid basic header. Credentials not correctly base64 encoded'
 </s> add             msg = _("Invalid basic header. Credentials not correctly base64 encoded.") </s> remove             msg = 'Invalid basic header. Credentials string should not contain spaces.'
 </s> add             msg = _("Invalid basic header. Credentials string should not contain spaces.") </s> remove             raise exceptions.AuthenticationFailed('User inactive or deleted')
 </s> add             raise exceptions.AuthenticationFailed(_("User inactive or deleted")) </s> remove     message = _('This field must be unique for the "{date_field}" date.')
 </s> add     message = _("This field must be unique for the \"{date_field}\" date.")
            error_format = _("Invalid page ({page_number}): {message}.")
  
          try:
              page = paginator.page(page_number)
          except InvalidPage as exc:
            error_format = _("Invalid page ({page_number}): {message}.")
              raise NotFound(error_format.format(
                  page_number=page_number, message=six.text_type(exc)
              ))
  
          return page
keep keep keep keep replace keep keep keep keep keep
 use double quotes for user visible strings; end user visible strings in full stops; add some missing translation tags 
rest_framework/generics.py