<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_formatter_by_name(_alias, **options):
 """Lookup and instantiate a formatter by alias. Raises ClassNotFound if not found. """

    cls = find_formatter_class(_alias)
    if cls is None:
        raise ClassNotFound("no formatter found for name %r" % _alias)
    return cls(**options)