Get a chart

def chart(self, x=None, y=None, chart_type=None, opts=None,
			  style=None, label=None, options={}, **kwargs):
		"""
		Get a chart
		"""
		try:
			self.chart_obj = self._chart(x, y, chart_type, opts, style, label,
										 options=options, **kwargs)
		except Exception as e:
			self.err(e, self.chart, "Can not create chart")