Number of points in .las by PDAL from Python

Question

I need to recieve the number of points that .las file has from Python and save it as variable. For now I'm doing it like this:

def execute(self, pipeline):
    pipeline = pdal.Pipeline(json.dumps(pipeline))
    pipeline.validate()
    self.points_num += int(pipeline.execute())

def points(self, file):
    pipeline = [
        file,
        {
            "type": "filters.info",
        }
    ]
    self.execute(pipeline)

However when file is big (above 2Gb) the procedure takes up to 4 minutes. Is there a smarter way to get number of points?