Kent Johnson said unto the world upon 16/09/06 07:49 PM:
> Brian van den Broek wrote:
>> Kent Johnson said unto the world upon 16/09/06 04:35 PM:
>>> Brian van den Broek wrote:
>
>>>> You say you are new to Python. Well, it might not now be obvious why
>>>> dictionaries are especially useful, but they are *central* to the
>>>> pythonic approach. The sooner you become comfortable with them, the
>>>> better (IMHO).
>>> I agree that dicts are extremely useful, but I don't think they add
>>> anything in this case unless there is actually a need for keyed
>>> access. A list of lists (or tuples) seems very appropriate to me. A
>>> good alternative might be a list of Bunches.
>>> http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/52308
>>>
>>> Kent
>>
>>
>> Hi Kent and all,
>>
>> I should have included the reason why I thought a dict might be better
>> here. (I did send it in a private email after the post.)
>>
>> A lot of ways I could imagine the time-line data being used might
>> involve wanting to access some one year, rather than the entire
>> time-line.
>
> Yes, I was a bit hasty in denouncing dicts, the best data structure does
> depend entirely on how it is to be used, and we don't know enough about
> this application to know.
Hi Kent and all,
I absolutely agree that my suggestions did get a bit ahead of the spec :-)
A combination of thinking about what *I* would want a yearly headline
program to do and wanting to encourage comfort with dicts ASAP is what
drove the suggestion. But, if the OP has a simpler spec than my
imaginary one . . . .
>> >>> print timeline_data[800][0]
>>
>> seems *way* better than something like:
>>
>> >>> for year_data in timeline_data_as_list_of_lists:
>> ... if year_data[0] == 800:
>> ... print year_data[1]
>> ... break
>>
>> which would be what the original list structure seems to require.
>
> The thing is, though, how will you know that 800 is a valid year? You
> need a list of valid years. If you get that list from the dict keys, and
> iterate that, you haven't really gained anything over a list of tuples.
> Maybe you have a lot of items and the user enters a year and you want to
> print out the data you have on the year...
def print_year_headline(year):
try:
print timeline_data[year][0]
except KeyError:
print "I am sorry; we have no data on year %s." %year
allows for random access by year while handling the problem.
But Kent's point about not getting too far ahead of the spec is surely
right.
To the OP: if Kent and I disagree, there are very good odds that
Kent's the one to listen to ;-)
Best to all,
Brian vdB
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