<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_job_class(klass_str):
 """ Return the job class """

    mod_name, klass_name = klass_str.rsplit('.', 1)
    try:
        mod = importlib.import_module(mod_name)
    except ImportError as e:
        logger.error("Error importing job module %s: '%s'", mod_name, e)
        return
    try:
        klass = getattr(mod, klass_name)
    except AttributeError:
        logger.error("Module '%s' does not define a '%s' class", mod_name, klass_name)
        return
    return klass