Hi, I see some code in strategy as follows:
def __init__(self): # To control operation entries self.orderid = None # Create SMA on 2nd data sma = btind.MovAv.SMA(self.data1, period=self.p.period) # Create a CrossOver Signal from close an moving average self.signal = btind.CrossOver(self.data1.close, sma)
I wonder why the sma isn't prefixed by self. while signal is. Is there any guidance tell us when to use self or not?