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AttributeError: 'Cerebro' object has no attribute '_exactbars'



  • I am working through the Quickstart guide, and just got to the sell section. All of a sudden, cerebro.plot() will not work, but cerebro.run() still does. When I run the code, no plot shows up in the output, but no error message, I only get the error message when I comment out cerebro.ruin(). I have seen this issue before on here, but it has been due to not adding data, although, I know that is not the case here. Thanks for the help!

     from __future__ import (absolute_import, division, print_function,
                            unicode_literals)
    
     import datetime  # For datetime objects
     import os.path  # To manage paths
     import sys  # To find out the script name (in argv[0])
    
    # Import the backtrader platform
    import backtrader as bt
    
    # Create a Stratey
    class TestStrategy(bt.Strategy):
    
        def log(self, txt, dt=None):
            ''' Logging function fot this strategy'''
            dt = dt or self.datas[0].datetime.date(0)
            print('%s, %s' % (dt.isoformat(), txt))
    
        def __init__(self):
            # Keep a reference to the "close" line in the data[0] dataseries
            self.dataclose = self.datas[0].close
            self.order = None
        
        def notify_order(self, order):
            if order.status in [order.Submitted, order.Accepted]:
                # Buy/Sell order submitted/accepted to/by broker - Nothing to do
                return
    
            # Check if an order has been completed
            # Attention: broker could reject order if not enough cash
            if order.status in [order.Completed]:
                if order.isbuy():
                    self.log('BUY EXECUTED, %.2f' % order.executed.price)
                elif order.issell():
                    self.log('SELL EXECUTED, %.2f' % order.executed.price)
    
                self.bar_executed = len(self)
    
            elif order.status in [order.Canceled, order.Margin, order.Rejected]:
                self.log('Order Canceled/Margin/Rejected')
    
            # Write down: no pending order
            self.order = None
    
        def next(self):
            # Simply log the closing price of the series from the reference
            self.log('Close, %.2f' % self.dataclose[0])
    
            # Check if an order is pending ... if yes, we cannot send a 2nd one
            if self.order:
                return
    
            # Check if we are in the market
            if not self.position:
    
                # Not yet ... we MIGHT BUY if ...
                if self.dataclose[0] < self.dataclose[-1]:
                        # current close less than previous close
    
                        if self.dataclose[-1] < self.dataclose[-2]:
                            # previous close less than the previous close
    
                            # BUY, BUY, BUY!!! (with default parameters)
                            self.log('BUY CREATE, %.2f' % self.dataclose[0])
    
                            # Keep track of the created order to avoid a 2nd order
                            self.order = self.buy()
    
            else:
    
                # Already in the market ... we might sell
                if len(self) >= (self.bar_executed + 5):
                    # SELL, SELL, SELL!!! (with all possible default parameters)
                    self.log('SELL CREATE, %.2f' % self.dataclose[0])
    
                    # Keep track of the created order to avoid a 2nd order
                    self.order = self.sell()
    
    
    if __name__ == '__main__':
        # Create a cerebro entity
        cerebro = bt.Cerebro()
    
        # Add a strategy
        cerebro.addstrategy(TestStrategy)
    
        # Datas are in a subfolder of the samples. Need to find where the script is
        # because it could have been called from anywhere
        modpath = os.path.dirname(os.path.abspath(sys.argv[0]))
        datapath = os.path.join(modpath, '../../datas/orcl-1995-2014.txt')
    
        # Create a Data Feed
        data = bt.feeds.YahooFinanceData(
            dataname="AAPL",
            # Do not pass values before this date
            fromdate=datetime.datetime(2010, 1, 1),
            # Do not pass values before this date
            todate=datetime.datetime(2010, 12, 31),
            # Do not pass values after this date
            reverse=False)
    
        # Add the Data Feed to Cerebro
        cerebro.adddata(data)
    
        # Set our desired cash start
        cerebro.broker.setcash(100000.0)
        
        cerebro.broker.setcommission(commission = .001)
    
        # Print out the starting conditions
        print('Starting Portfolio Value: %.2f' % cerebro.broker.getvalue())
    
        # Run over everything
        cerebro.run()
        cerebro.plot()
    
        # Print out the final result
        print('Final Portfolio Value: %.2f' % cerebro.broker.getvalue())
    

  • administrators

    If nothing is plotted ... your data is empty. As simple as that. A simple print in your next method will do the trick.



  • @backtrader it can't be that, because it does print daily price points and the buy and sell numbers


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