The get_loc() method of the Index class in pandas does not have a method argument.

[chekh]

Expected Behavior

Executing Backtest.plot() raise an exception in
backtesting._plotting module in function def _group_trades(column).

new_bar_idx = new_index.get_loc(mean_time, method='nearest')
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: Index.get_loc() got an unexpected keyword argument 'method'

The get_loc() method of the Index class in pandas does not have a method argument.

Original code which is rising exception:

    def _group_trades(column):
        def f(s, new_index=pd.Index(df.index.view(int)), bars=trades[column]):
            if s.size:
                # Via int64 because on pandas recently broken datetime
                mean_time = int(bars.loc[s.index].view(int).mean())
                new_bar_idx = new_index.get_loc(mean_time, method='nearest')
                return new_bar_idx
        return f

As a solution the following code snippet may be applied:

    def _group_trades(column):
        def f(s, new_index=pd.Index(df.index.view(int)), bars=trades[column]):
            if s.size:
                # Via int64 because on pandas recently broken datetime
                mean_time = int(bars.loc[s.index].view(int).mean())

                new_bar_idx = new_index.searchsorted(mean_time, side='left')

                return new_bar_idx
        return f

Additional info

• Backtesting version: 0.3.3
• pandas version: 2.1.3

[craquinterogo]

For some reason the version when installed by pip doesn't work, but installing by using "pip install -e <repository_path>" works perfectly.

[RaccoonTrading]

Patch works great thx !