I'm trying to extend two lists of lists in python, so that item 1 of the first list of lists extends with item 1 of the second list of lists, and so forth.
I'm new to this and self-taught, so could be missing something very simple, but I can't find an answer anywhere.
This is what I feel the code should be, but obviously not working.

```
list1[x].extend(list2[x]) for x in list1

```

What I'm trying to achieve is this:

```
list1 = [[1,2,3],[4,5,6],[7,8,9]]
list2 = [[a,b,c],[d,e,f],[g,h,i]]

output = [[1,2,3,a,b,c],[4,5,6,d,e,f],[7,8,9,g,h,i]]

```

Any ideas?