Hello,
Thank you for reaching out to us. For me to further troubleshoot this concern, could you please provide me with your customer client ID that you’re running the getcampaign.py code against? If you run queries to get campaigns against an MCC account, you will receive nothing, as MCC accounts themselves do not manage campaigns, but manage accounts that manage campaigns. Let me know if you have further questions.
Thank you,
Bryan, Google Ads API Team