Start trading from 2nd candle

[A Former User]

Greetings,

My strategy is as follows:

    get last 2 days daily OHLC bars (today's and yesterday's bar)
    if there is gap up
        get today's 15 minute Bars
            if the opening bar is red, place sell order on 2nd bar open
            if the opening bar is green, place buy order on 2nd bar open```

I am not sure how to customize the `Strategy`'s `next()` function to trade using this logic.

My code is as follows:
```python
import backtrader as bt
from backtrader import order # Import the backtrader platform
import pandas
from backtest import TestStrategy
from datetime import datetime, timedelta
import yfinance

class Backtest():
    def __init__(self) -> None:
        self.today = datetime.today()
        self.yesterday = self.today - timedelta(days=1)
    def symbols_list(self):
        try:
            url = "https://archives.nseindia.com/content/indices/ind_nifty50list.csv"
            self.symbols_list = pandas.read_csv(url, usecols=[2], names=['symbol'], header = 0)
            self.symbols_list['gap'] = 0 
        except Exception as e:
            print(e)
        
    def check_gap(self):
        for index, row in self.symbols_list.iter_rows():
            # get last 2 days candles from Yahoo Finance
            ticker = yfinance.Ticker(row['symbol'] + ".NS")
            self.symbol_hist_df = ticker.history(start=self.today, end=self.yesterday, interval='1d')
            # gap up gap down check
            if self.symbol_hist_df['Open'][-1] > self.symbol_hist_df['High'][-2]:
                self.symbols_list['gap'][index] == 1 # gap up
            elif self.symbol_hist_df['Open'][-1] < self.symbol_hist_df['Low'][-2]:
                self.symbols_list['gap'][index] == -1 # gap down
            else:
                self.symbols_list['gap'][index] == 0 # no signal

    def run_backtest(self):
        # Create a cerebro entity
        self.cerebro = bt.Cerebro()
        # Create a Data Feed
        data = bt.feeds.PandasData(dataname=yfinance.download('TSLA', '2018-01-01', '2019-01-01'))
        # # Add the Data Feed to Cerebro
        self.cerebro.adddata(data)
        # Set our desired cash start
        self.cerebro.broker.setcash(1000.0)
        # Add a FixedSize sizer according to the stake
        self.cerebro.addsizer(bt.sizers.FixedSize, stake=10)
        # Set the commission
        self.cerebro.broker.setcommission(commission=0.0)
        for index, row in self.symbols_list.iter_rows():
            if row['gap'] == 1: # gap up strategy
                # Add gap up strategy
                self.strats = self.cerebro.optstrategy(TestStrategy)
            if row['gap'] == -1: # gap up strategy
                # Add gap down strategy
                self.strats = self.cerebro.optstrategy(TestStrategy)
        # Run over everything
        self.cerebro.run(maxcpus=1)

[A Former User]

@backtrader could you kindly help me here ?
I am unable to proceed. I need help and I am unable to figure this out on my own.

I need to check if the 1st 15 minute bar is a red or green bar. (I know how to calculate red and green bar.) I am not sure where i need to add this check so that next() will start placing trades from the 2nd candle.