@ab_trader Thank you for taking the time to reply.
But I didn't get what was wrong exactly. I made the change and the error is gone.

Hi guys, need a little help
I tested building a custom indicator with the help of the Backtrader documentation and I got an AttributeError. I am new to Backtrader and I'd appreciate a little help.
Code```

import backtrader as bt
import backtrader.indicators as btind
class DummyInd(bt.Indicator):
    lines = ('dummyline',)

    params = (('value', 5),)

    def __init__(self):
        self.lines.dummyline = bt.Max(0.0, self.params.value)
class MyStrategy(bt.Strategy):
    def __init__(self):
        self.rocp = btind.DummyInd()
    def next(self):
        print(self.rocp)

cerebro = bt.Cerebro()  # create a "Cerebro" engine instance

# Create a data feed
data = bt.feeds.YahooFinanceData(dataname='sunpharma.csv')

cerebro.adddata(data)  # Add the data feed

cerebro.addstrategy(MyStrategy)  # Add the trading strategy
print('Starting Portfolio Value: ',cerebro.broker.getvalue())
cerebro.run()  # run it all
print('Final Portfolio Value: ',cerebro.broker.getvalue())
cerebro.plot()  # and plot it with a single command