IndicatorBars.Count

int Count {get;}

indicatorBars.Count: int

public partial class BarsCopy : Indicator
{
    public override void Calculate(int index)
    {
        var bar = Bars[index];
        Result[index] = new OhlcvBar(bar.Open, bar.High, bar.Low, bar.Close, bar.TickVolume);
        if (IsLastBar)
            Print("Output bars count: {0}", Result.Count);
    }
}

def calculate(self, index):
    bar = api.Bars[index]
    api.Result[index] = OhlcvBar(bar.Open, bar.High, bar.Low, bar.Close, bar.TickVolume)
    if api.IsLastBar:
        api.Print(f"Output bars count: {api.Result.Count}")

{
  "AccessRights": "None",
  "IsOverlay": false,
  "BarOutputs": [
    {
      "Name": "Result",
      "DisplayName": "Main"
    }
  ]
}