test_module.py

import backtrader as bt


# Create a Stratey
class TestStrategy(bt.Strategy):
    params = (("exitbars", 5),)

    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

        # To keep track of pending orders and buy price/commission
        self.order = None
        self.buyprice = None
        self.buycomm = 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, Price: %.2f, Cost: %.2f, Comm %.2f"
                    % (order.executed.price, order.executed.value, order.executed.comm)
                )

                self.buyprice = order.executed.price
                self.buycomm = order.executed.comm
            else:  # Sell
                self.log(
                    "SELL EXECUTED, Price: %.2f, Cost: %.2f, Comm %.2f"
                    % (order.executed.price, order.executed.value, order.executed.comm)
                )

            self.bar_executed = len(self)

        elif order.status in [order.Canceled, order.Margin, order.Rejected]:
            self.log("Order Canceled/Margin/Rejected")

        self.order = None

    def notify_trade(self, trade):
        if not trade.isclosed:
            return

        self.log("OPERATION PROFIT, GROSS %.2f, NET %.2f" % (trade.pnl, trade.pnlcomm))

    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 + self.params.exitbars):
                # 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()