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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def normalize_choices(db_values, field_name, app=DEFAULT_APP, model_name='', human_readable=True, none_value='Null', 
                      blank_value='Unknown', missing_value='Unknown DB Code'):
    '''Output the human-readable strings associated with the list of database values for a model field.

    Uses the translation dictionary `CHOICES_<FIELD_NAME>` attribute for the given `model_name`.
    In addition, translate `None` into 'Null', or whatever string is indicated by `none_value`.
    '''
    if app and isinstance(app, basestring):
        app = get_app(app)
    if not db_values:
        return
    try:
        db_values = dict(db_values)
    except:
        raise NotImplemented("This function can only handle objects that can be converted to a dict, not lists or querysets returned by django `.values().aggregate()`.")

    if not field_name in db_values:
        return db_values
    if human_readable:
        for i, db_value in enumerate(db_values[field_name]):
            if db_value in (None, 'None') or app in (None, 'None'):
                db_values[field_name][i] = none_value
                continue
            if isinstance(db_value, basestring):
                normalized_code = str(db_value).strip().upper()
            # the app is actually the models.py module, NOT the app_name package
            # so don't look in app.models, you'll only find django.db.models there (app_name.models.models)
            choices = getattr(app, 'CHOICES_%s' % field_name.upper(), [])
            normalized_name = None
            if choices:
                normalized_name = str(choices.get(normalized_code, missing_value)).strip()
            elif normalized_code:
                normalized_name = 'DB Code: "%s"' % normalized_code
            db_values[field_name][i] = normalized_name or blank_value
    else:
        raise NotImplemented("This function can only convert database choices to human-readable strings.")
    return db_values