def params_get(path, params):
    """Read a key/path from loaded params.

    Parameters
    ----------
    path : str
      The .-delimited path to the value to return. Currently supports dict keys
      but not numeric array indices.

    params : dict
      Params as read using read_params().
    """
    r = params
    for p in path.split("."):
        r = r[p]
    return r