<p>I have a list of 2-item tuples and I'd like to convert them to 2 lists where the first contains the first item in each tuple and the second list holds the second item.</p>

<p><strong>For example:</strong></p>

<pre><code>original = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
# and I want to become...
result = (['a', 'b', 'c', 'd'], [1, 2, 3, 4])
</code></pre>

<p>Is there a builtin function that does that?</p>

```
zip
```
is its own inverse! Provided you use the special * operator.
```
```
>>> zip(*[('a', 1), ('b', 2), ('c', 3), ('d', 4)])
[('a', 'b', 'c', 'd'), (1, 2, 3, 4)]
```
```
The way this works is by calling
```
zip
```
with the arguments:
```
```
zip(('a', 1), ('b', 2), ('c', 3), ('d', 4))
```
```
… except the arguments are passed to
```
zip
```
directly (after being converted to a tuple), so there's no need to worry about the number of arguments getting too big.