Gloom Demon schreef:
> Hello :-)
>
> I am reading Ivan van Leiningem "Learn Python in 24 hours" and I am
> having problems understanding the way arrays work in Python. I used to
> know Pascal and arrays there were tablelike.
>
> Example (cost of something in different countries by different years)
>
> Record1 US 2006 22.10
> Record2 US 2007 23.45
> Record3 UK 2007 22.90
> ..................................
> RecordN ....................
That is an array of records. In Pascal you can also have e.g. an array
of integers, and it is a sequential list just as in Python. What makes
it table-like is that you have an array not of scalars but of records.
> However in Python, if I understand correctly this example would look
> like this:
>
> US 2006 22.10 US 2007 23.45 UK 2007 22.90 ........................
You could do it like that, but there are better ways. You could make a
list of tuples, which would be more or less equivalent to your Pascal
array of records. A simple example, presuming you read the values from a
file:
lst = []
for line in countryfile:
country, year, amount = line.split()
year = int(year)
amount = float(amount)
lst.append((country, year, amount))
That would look like:
[
('US', 2006, 22.10),
('US', 2007, 23.45)
...
]
Then you could scan through it like this:
for record in lst:
if record[0] == 'US':
...
--
The saddest aspect of life right now is that science gathers knowledge
faster than society gathers wisdom.
-- Isaac Asimov
Roel Schroeven
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