def get_cache_filename(self, cache_directory=None):
        if cache_directory == None:
            cache_directory = self.get_cache_directory()
        filename = self.cache_filename_format.format(self.station)
        return os.path.join(cache_directory, filename)
dataset/ETHPy150Open impactlab/eemeter/eemeter/weather.py/CachedWeatherSourceBase.get_cache_filename/operator `is` -> `==`