Backtesting.py支持多种数据源，但目前还不支持TV数据源，因此需要使用其他数据源。以下是使用Backtesting.py中Yahoo数据源的示例代码：

from backtesting import Backtest, Strategy
from backtesting.lib import SignalStrategy, TrailingStrategy
from backtesting.lib import crossover

from backtesting.test import SMA, GOOG

class SmaCross(SignalStrategy, TrailingStrategy):
    n1 = 10
    n2 = 20
    def init(self):
        super().init()
        # Precompute the two moving averages
        self.ma1 = self.I(SMA, self.data.Close, self.n1)
        self.ma2 = self.I(SMA, self.data.Close, self.n2)
        # Keep track of pending orders
        self.buy_price = 0
        self.sell_price = 0
    def next(self):
        super().next()
        # Buy and sell signals
        if crossover(self.ma1, self.ma2):
            self.buy_signal(self.data.Close[0])
            self.sell_price = self.ma1[-1]
        elif crossover(self.ma2, self.ma1):
            self.sell_signal(self.data.Close[0])
            self.buy_price = self.ma2[-1]
        # Trailing stop loss based on the moving average
        if self.position:
            if self.position.is_long:
                self.trailing_stop(self.buy_price)
            elif self.position.is_short:
                self.trailing_stop(self.sell_price)

bt = Backtest(GOOG, SmaCross, cash=10000, commission=.002)
output = bt.run()
print(output)
output.plot()