Looking at the current IBP Python SDK ( https://github.com/IBM-Blockchain/ibp-python-sdk ) I can't find any calls for invoking chaincode transactions (adding data in the ledger and querying it). Will this functionality be added later?
This SDK is only for the managing of the IBM Blockchain Platform itself and is not an SDK for interacting with a Hyperledger Fabric network created on IBM Blockchain Platform. You should look to the various hyperlegdger fabric SDKs themselves for that capability. IBM provides documentation about this which you can find here https://cloud.ibm.com/docs/blockchain?topic=blockchain-ibp-console-app
Note that it doesn't list the hyperledger fabric Python SDK because it's not recommended for use with IBM Blockchain Platform.