How to ignore - ERROR: The system was unable to find the specified registry key or va

[asheru93]

def isAlreadyInstalled(lookupRegistryKey):
    consoleLines = os.popen('reg query "' + APP_REGISTRY_KEY + "\\" + VERSION_SYSTEM_NAME + '"').readlines()
    if len(consoleLines) == 0:
        return False
    return True

I have this snippet. The problem is that it gives this error in the command line without stoping the execution ( wich is ok for my cas), I just want to ignore this error.

ERROR: The system was unable to find the specified registry key or value.