layer = QgsVectorLayer(r'//Users//rwegener//repos//correlations//co_energy_weather_shpfiles//co_energy_weather.shp',
                   'degree_days', "memory")
if not layer.isValid():
    print('layer failed to load')

layer = QgsVectorLayer(r'/Users//rwegener//repos//correlations//co_energy_weather_shpfiles//co_energy_weather.shp',
                   'degree_days', "memory")
layer = QgsVectorLayer(r'/Users/rwegener/repos/correlations/co_energy_weather_shpfiles/co_energy_weather.shp',
                   'degree_days', "memory")
layer = QgsVectorLayer(r'\Users\rwegener\repos\correlations\co_energy_weather_shpfiles\co_energy_weather.shp',
                   'degree_days', "memory")

layer = iface.addVectorLayer(r'//Users//rwegener//repos//correlations//co_energy_weather_shpfiles//co_energy_weather.shp',
                   'degree_days', "memory")