[Tutor] Alternative to nested loops

[Steve Nelson]

On 3/19/06, John Fouhy <john at fouhy.net> wrote:

> What you're doing is called "flattening" a list.  You can do it with a
> list comprehension:
>
> >>> foo = [[1,2,3], [4,5,6], [7,8,9]]
> >>> [x for y in foo for x in y]
> [1, 2, 3, 4, 5, 6, 7, 8, 9]

Ah yes, that was the sort of thing I was thinking of.

> If you want to sum, you could also use a generator expression
> (requires Python 2.4):

I am on 2.3.5 so I can do sum([x for y in foo for x in y])

So now looking at both your and Karl's ways, how do I catch
exceptions.  My current (working) code looks like this:

def fleetHealth(self):
    """Iterate through each square to see if the whole fleet has been sunk."""
    s = 0
    for c in self.ranks:
        for b in c:
          try:
            s += b.contents.size()
          except:
            pass
    return s

I guess this could be significantly refactored!  But... readability counts!

S.