def is_unknown(value):
    unk_vals = ['na', 'n/a', 'unk', 'unknown', '']
    try:
        if value.strip().lower() in unk_vals:
            return True
        else:
            return False
    except AttributeError:
        return False
    except TypeError:
        return False
Set the input delimiter.  Can be a fixed string of any length, an integer, or None
dataset/ETHPy150Open kenfar/DataGristle/gristle/field_type.py/is_unknown--crossover with--dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/asynchat.py/async_chat.set_terminator