[Tutor] Reading only a few specific lines of a file

[John Fouhy]

On 23/05/2008, Jason Conner <jasonbconner at gmail.com> wrote:

Hi Jason,

> def loadItem(self, objectToLoad):
>     x = 0
>     wordList = []
>     fobj = file()
>     fobj.open("itemconfig.txt", 'rU')
>
>     for line in fobj.readline():

In recent pythons, you can write this better as:
  for line in fobj:

Once you've done this, you can use .next() to advance the iterator.  e.g.:

for line in fobj:
  if line == objectToLoad:
    wordList.append(line)
    wordList.append(fobj.next())

This will save the line that matched and the line following it.  Note
that this means you won't check the second line --- you can maybe
visualise this with a simpler example:

>>> a = []
>>> nums = iter(range(10))
>>> for i in nums:
...  a.append((i, nums.next()))
...
>>> a
[(0, 1), (2, 3), (4, 5), (6, 7), (8, 9)]

-- 
John.