Long story short, I am trying to work with some crazy data I collected yesterday. A quick nested for loop would do this real easy but right now, I just want to get my nested list comprehension to work. There are a bunch of post on this subject and I am not sure whether it is just me or the because of Friday evening, I can't get it to work. My list comphrension is in format:

```
[ [str(j[0], sanitize(j[1]) for j in i.split(',')] for i in b]

```

where b is `['string, float\t\n', 'string, float\t\n']` or b might be a file object or whatever, doesn't matter a heck lot.

I could simply do something like

```
for i in b:
    out.append(str(j[0]), sanitize(j[1])

```

But, it should be possible by list comprehension. IT SHOULD!!! And, somehow, I am not getting it right.

Now, on to what I have done so far...

```
>>> b
['08:54:55, 0.031250\n', '08:55:57, 0.031250\n']

>>> [i.split(',') for i in b]
[['08:54:55', ' 0.031250\n'], ['08:55:57', ' 0.031250\n']]

```

What I want:

```
[['08:54:55', 0.031250], ['08:55:57', 0.031250]]

```

A multiple list comprehension should do the trick:

Something like:

```
[ [j[0], j[1]] for j in i.split(',') for i in b] # the cleaning/str/float would be something like: str(j[0]), float(j[1])

```

BUT, this is what I get.

```
>>> [ [j[0], j[1]] for j in i.split(',') for i in b]
[['0', '8'], ['0', '8'], [' ', '0'], [' ', '0']]
>>> 
>>> [ [j[1]] for j in i.split(',') for i in b]
[['8'], ['8'], ['0'], ['0']]

```

Any attempt to work on j[0] or j[1] does not pan out.

To figure out what was going on, I did this:

```
>>> [ [ pprint(type(j)) for j in i.split(',')] for i in b]
<type 'str'>
<type 'str'>
<type 'str'>
<type 'str'>
[[None, None], [None, None]]

```

If I don't mess with `j[0]` or `j[1]`,

```
>>> [ [ j for j in i.split(',')] for i in b]
[['08:54:55', ' 0.031250\n'], ['08:55:57', ' 0.031250\n']]

```

The example with `pprint(type(j))` means even if I were to write an external function, it would not do the trick. I would simply be getting an empty list back from the list comprehension.

What am I doing wrong? A lambda might do the trick?