That's actually pure python, multiplies the list `N` times is, the same behavior it would have with a string:

``` python
>>> 'Na'*20 + ' Batman'
'NaNaNaNaNaNaNaNaNaNaNaNaNaNaNaNaNaNaNaNa Batman'
>>> [1]*10
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
```