<filename>config.py

class Constants:
    COMPORT = '/dev/ttyUSB0'
    ENDPOINT = 'aaaaaaaa.iot.ap-northeast-1.amazonaws.com'
    PORT = 8883
    SCRIPTDIR= '/home/user/iot_ws/aws_iot_sensor_hub/'
    ROOTCA = SCRIPTDIR + 'cert/AmazonRootCA1.pem'
    CERT = SCRIPTDIR + 'cert/certificate.pem.crt'
    PRIVATEKEY = SCRIPTDIR + 'cert/private.pem.key'
<filename>config.py

class Constants:
    COMPORT = '/dev/ttyUSB0'
    ENDPOINT = 'aaaaaaaa.iot.ap-northeast-1.amazonaws.com'
    PORT = 8883
    SCRIPTDIR= '/home/user/iot_ws/aws_iot_sensor_hub/'
    ROOTCA = SCRIPTDIR + 'cert/AmazonRootCA1.pem'
    CERT = SCRIPTDIR + 'cert/certificate.pem.crt'
    PRIVATEKEY = SCRIPTDIR + 'cert/private.pem.key'