class StoreError(RuntimeError): pass class CredentialsNotFound(StoreError): pass class InitializationError(StoreError): pass def process_store_error(cpe, program): message = cpe.output.decode('utf-8') if 'credentials not found in native keychain' in message: return CredentialsNotFound(f'No matching credentials in {program}') return StoreError(f'Credentials store {program} exited with "{message}".')