I have a list such as:

```
my_list = [[1,2,2,1], [0,0,1,2], [1,2,0,0], [1,0,0,1]]

```

I need to remove only the leading and trailing zeros from the inner lists, so that I end up with:

```
new_list = [[1,2,2,1], [1,2], [1,2], [1,0,0,1]]

```

Any help much appreciated.