Creating a new class

The ExponentialMovingAverage class in QuantConnect does not require a "tick" parameter because it is designed to update its value based on the time and price information you provide when calling the Update method.

In your selection_data class, you have defined two ExponentialMovingAverage objects, self.slow and self.fast, with periods of 200 and 50 respectively. These objects are initialized when you create an instance of the selection_data class.

The update method in your class takes time and price as parameters and uses these to update the ExponentialMovingAverage objects. This is done by calling the Update method on self.fast and self.slow and passing the time and price parameters to it.

The is_ready method checks if both ExponentialMovingAverage objects are ready by calling their IsReady property. This property returns True if the indicator is ready and False otherwise.

Here is the relevant part of your code:

class selection_data:            
   def __init__(self):
       self.slow = ExponentialMovingAverage(200)
       self.fast = ExponentialMovingAverage(50)

   def is_ready(self):
       return self.slow.IsReady and self.fast.IsReady

   def update(self, time, price):
       self.fast.Update(time, price)
       self.slow.Update(time, price)

This code is consistent with the examples provided in the QuantConnect forum.