AttributeError: 'Lines_LineSeries_LineIterator_DataAccessor_Indicat' object has no attribute '_addobserver'

marsario

Hi, I'm learning to make a new indicator.

I've been following these two pages:

When I paste the code, I get the same error message:
AttributeError: 'Lines_LineSeries_LineIterator_DataAccessor_Indicat' object has no attribute '_addobserver'

What is the problem?

This is my full code:

import datafeeds.yf as yf
import backtrader as bt
import datetime


enddate=datetime.date.today()
startdate = enddate - datetime.timedelta(days=(365*10))
cerebro = bt.Cerebro()
#Adding apple datafeed to cerebro:
cerebro = yf.apple(cerebro,startdate,enddate)
cerebro.broker.setcash(100000.0)
print("Launching the strategy")
cerebro.addstrategy(DummyDifferenceDivider)
cerebro.run()
print("Strategy is over, final cash:",cerebro.broker.getvalue())
cerebro.plot()

class DummyDifferenceDivider(bt.Indicator):
    lines = ('diffdiv',)  # output line (array)
    params = (
        ('period', 1),  # distance to previous data point
        ('divfactor', 2.0),  # factor to use for the division
    )
    def __init__(self):
        diff = self.data(0) - self.data(-self.p.period)
        diffdiv = diff / self.p.divfactor
        self.lines.diffdiv = diffdiv

marsario

I just realized that I only created an indicator, but no strategy and they are two totally different things lol. All clear