Issue in Class Sentiment

[gowrijp]

When you execute cerebro.run() you get the error as given below:
Starting Portfolio Value: 100000.00

TypeError Traceback (most recent call last)
in
147 cerebro.broker.setcommission(commission=0.001)
148 print('Starting Portfolio Value: %.2f' % cerebro.broker.getvalue())
--> 149 cerebro.run()
150 print('Final Portfolio Value: %.2f' % cerebro.broker.getvalue())
151

~\Anaconda3\lib\site-packages\backtrader\cerebro.py in run(self, **kwargs)
1125 # let's skip process "spawning"
1126 for iterstrat in iterstrats:
-> 1127 runstrat = self.runstrategies(iterstrat)
1128 self.runstrats.append(runstrat)
1129 if self._dooptimize:

~\Anaconda3\lib\site-packages\backtrader\cerebro.py in runstrategies(self, iterstrat, predata)
1291 self._runonce_old(runstrats)
1292 else:
-> 1293 self._runonce(runstrats)
1294 else:
1295 if self.p.oldsync:

~\Anaconda3\lib\site-packages\backtrader\cerebro.py in _runonce(self, runstrats)
1650 '''
1651 for strat in runstrats:
-> 1652 strat._once()
1653 strat.reset() # strat called next by next - reset lines
1654

~\Anaconda3\lib\site-packages\backtrader\lineiterator.py in _once(self)
295
296 for indicator in self._lineiterators[LineIterator.IndType]:
--> 297 indicator._once()
298
299 for observer in self._lineiterators[LineIterator.ObsType]:

~\Anaconda3\lib\site-packages\backtrader\lineiterator.py in _once(self)
315 # indicators are each called with its min period
316 self.preonce(0, self._minperiod - 1)
--> 317 self.oncestart(self._minperiod - 1, self._minperiod)
318 self.once(self._minperiod, self.buflen())
319

~\Anaconda3\lib\site-packages\backtrader\indicator.py in oncestart_via_nextstart(self, start, end)
122
123 self.advance()
--> 124 self.nextstart()
125
126 def once_via_next(self, start, end):

~\Anaconda3\lib\site-packages\backtrader\lineiterator.py in nextstart(self)
345
346 # Called once for 1st full calculation - defaults to regular next
--> 347 self.next()
348
349 def next(self):

in next(self)
26 self.sentiment = date_sentiment[date]
27 prev_sentiment = self.sentiment
---> 28 self.lines.sentiment[0] = self.sentiment
29
30

~\Anaconda3\lib\site-packages\backtrader\linebuffer.py in setitem(self, ago, value)
220 value (variable): value to be set
221 '''
--> 222 self.array[self.idx + ago] = value
223 for binding in self.bindings:
224 binding[ago] = value

TypeError: must be real number, not LineBuffer

Can you please tell me as to what needs to be changed?
I believe self.sentiment is not defined appropriately due to which the error is arising!