Merge pull request #595 from bmispelon/patch-1

        except VariableDoesNotExist:

            return ''

        except (ValueError, TypeError):

            raise TemplateSyntaxError("widthratio final argument must be an number")

            raise TemplateSyntaxError("widthratio final argument must be a number")

        try:

            value = float(value)

            max_value = float(max_value)