(field)
return NOT(empty(field))
Only return docs with a real, non-null value for ``field``
Only return docs with a real, non-null value for ``field``
Only return docs with a real non - null value for field
def non_null(field):
    """Only return docs with a real, non-null value for ``field``"""
    return NOT(empty(field))
def non_null ( field ) : return NOT ( empty ( field ) )