Python Argparse: Return only value without parameter name

Question

I want to access and argument from my Python script using argparse:

parser = argparse.ArgumentParser()

# Required positional argument
parser.add_argument('mode', type=str, 
                    help='Operation mode. Either "one" or "two".')

args = parser.parse_args()

print("Argument values:")
print(args.mode)

The variable "args.mode" contains the parameter name plus the value, like this "--mode One". But I want only the value part ("One"). I know I could split up the string but I want to know WHY argparse returns the parameter name. Is there a way to tell it I only want the value?