def create_scalar_summary(name, v):
    """
    Args:
        name (str):
        v (float): scalar value
    Returns:
        tf.Summary: a tf.Summary object with name and simple scalar value v.
    """
    assert isinstance(name, six.string_types), type(name)
    v = float(v)
    s = tf.Summary()
    s.value.add(tag=name, simple_value=v)
    return s