SystemExit: 2 error when calling parse_args() while using MTCNN

I am using: from facenet_pytorch import MTCNN
I am getting this error while running following code.
parser = argparse.ArgumentParser()
parser.add_argument(“-i”, “–input”, required = True,
help = ‘path to the input data’)
#parser.add_argument(“-f”, required=False)

args = vars(parser.parse_args(“-i /–input”))
This error has been written while running this code
usage: [-h] -i INPUT error: the following arguments are required: -i/–input
An exception has occurred, use %tb to see the full traceback.

I don’t understand how to solve this error. I am first time using MTCNN and argparse. Please help me to solve this error. Thank you in advance