(cls, chart_name)
return chart_class
Retrieves a class object of a specific chart.

        Args:
            chart_name (unicode): name of the chart to retrieve.

        Returns:
            Chart class object or None if not existing.
Retrieves a class object of a specific chart.
Retrieves a class object of a specific chart .
def get_chart(cls, chart_name):
        """Retrieves a class object of a specific chart.

        Args:
            chart_name (unicode): name of the chart to retrieve.

        Returns:
            Chart class object or None if not existing.
        """
        try:
            chart_class = cls._class_registry[chart_name.lower()]
        except KeyError:
            raise KeyError(
                'No such chart type: {0:s}'.format(chart_name.lower()))
        return chart_class
def get_chart ( cls , chart_name ) : try : chart_class = cls . _class_registry [ chart_name . lower ( ) ] except KeyError : raise KeyError ( 'No such chart type: {0:s}' . format ( chart_name . lower ( ) ) ) return chart_class