# How to flatten a list in Python?

You can flatten a list in python using the following one-liner:

```python
flat_list = [item for sublist in l for item in sublist]
```

In the example above, `l` is the list of lists that is to be flattened.

The previous example can be rewritten to be more readable and will look like this:

```python
flat_list = []
for sublist in l:
    for item in sublist:
        flat_list.append(item)
```

You can wrap this functionality into a function if you prefer:

```python
def flatten(l):
    return [item for sublist in l for item in sublist]
```