Hello everyone, I am very very new for this technology. I am using Python

Can you please help me to figure out how to read the data value from Quandl.
I am trying to get VIX close value . after call AddData function in the Initialize(), 

Is there anyway I can read the data I added from slice in OnData() ? Please let me know how . Thank you


  def Initialize(self):

        self.quandlCode = "CHRIS/CBOE_VX1"
        self.AddData[QuandlFuture](self.quandlCode, Resolution.Daily)

def OnData(self, slice):

     !!!!!!!!!!!!!help, what I can do here to get my VX value ?


class QuandlFuture(Quandl):

    def __init__(self):
        self.ValueColumnName = "Close"