这个问题通常是由于使用了较旧版本的 Matplotlib 或 Pandas.Locators 中的 RRuleLocator 导致的。解决方法是升级 Matplotlib 和 Pandas.Locators 到最新版本。如果你不想升级这些库，也可以手动更改一下使用 RRuleLocator 的部分代码，将 RRuleLocator 更改为 DateFormatter 或其他 Locator 类型。以下是一个使用 DateFormatter 的示例代码：

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import backtrader as bt

class MyStrategy(bt.Strategy):

    def __init__(self):
        self.dataclose = self.datas[0].close

    def next(self):
        self.log('Close: %.2f' % self.dataclose[0])

if __name__ == '__main__':
    cerebro = bt.Cerebro()

    # Create a Data Feed
    data = bt.feeds.YahooFinanceData(dataname='AAPL',
                                     fromdate=datetime.datetime(2010, 1, 1),
                                     todate=datetime.datetime(2017, 1, 1))

    cerebro.adddata(data)

    # Set our desired cash start
    cerebro.broker.setcash(100000.0)

    # Add the strategy
    cerebro.addstrategy(MyStrategy)

    # Add the analyzers we are interested in
    cerebro.addanalyzer(bt.analyzers.SharpeRatio, _name='mysharpe')
    cerebro.addanalyzer(bt.analyzers.DrawDown, _name='drawdown')
    cerebro.addanalyzer(bt.analyzers.TradeAnalyzer, _name='tradeanalyzer')

    # Run over everything
    results = cerebro.run()

    # Print Analyzers
    print(f'Sharpe Ratio: {results[0].analyzers.mysharpe.get_analysis()}')
    print(f'Max Drawdown: {results[0].analyzers.drawdown.get_analysis()}')
    print(f'Trade Analyzer: {results[0].analyzers.tradeanalyzer.get_analysis()}')

    # Plot the result
    plt.rcParams['figure.figsize'] = [15, 8]
    plt.rcParams['figure.dpi'] = 200
    plt.rcParams['savefig.dpi'] = 300

    cerebro.plot(style='candlestick',
                 barup='green',
                 bardown='red',
                 fmt_x_ticks='%Y-%m-%d',
                 fmt_x_data='%Y-%m-%d',
                 xrotation=45,
                 numfigs=1)

在这个示例代码中，我们使用 DateFormatter