(v)
string to boolean
string to boolean
string to boolean
def str2bool(v):
    """string to boolean"""
    if v.lower() in ('yes', 'true', 't', 'y', '1'):
        return True
    elif v.lower() in ('no', 'false', 'f', 'n', '0'):
        return False
    else:
        raise argparse.ArgumentTypeError('Boolean value expected.')
def str2bool ( v ) : if v . lower ( ) in ( 'yes' , 'true' , 't' , 'y' , '1' ) : return True elif v . lower ( ) in ( 'no' , 'false' , 'f' , 'n' , '0' ) : return False else : raise argparse . ArgumentTypeError ( 'Boolean value expected.' )