Python method to "tap" a config object

tap.py

def dict_tap(path, default=None):
    """ Retrieves the path through a dictionary.
        "The config is a lot like an onion - it has layers"

        example:
        >>> dict_tap(
        >>>     'otp.age_threshold',
        >>>     default=2,
        >>> )
    """

    parts = path.split('.')

    layer = _CONFIG
    for part in parts:
        if part.isdigit():
            # Use part as an array index
            part = int(part)
            try:
                layer = layer[part]
            except IndexError:
                return default
        else:
            if not layer:
                return default

            layer = layer.get(part, default)
            if layer == default:
                return default

    return layer