<p>What's the difference between the list methods <code>append()</code> and <code>extend()</code>?</p>

```
append
```
appends a single element.
```
extend
```
appends a list of elements.
Note that if you pass a list to append, it still adds one element:
```
```
>>> a = [1, 2, 3]
>>> a.append([4, 5, 6])
>>> a
[1, 2, 3, [4, 5, 6]]
```
```