Tuple question
Wai Yip Tung
tungwaiyip at yahoo.com
Thu Sep 2 12:52:58 EDT 2004
Oops I misunderstood that you said about count and index. Now I got it.
Speaking as a user of Python, here is my take:
You consider tuple an immutable version of list. But in Python's design
they have different purpose. List a collection of homogeneous items, while
tuple is a convenient grouping of any kind of items. For example, you can
use them this way:
users = ['admin', 'user1', 'user2']
address = ('www.python.org', 80)
index and count only make sense when the collection is homogeneous.
Therefore they are not defined for tuple.
tung
On Thu, 02 Sep 2004 17:40:27 +0100, Will McGugan
<news at NOwillmcguganSPAM.com> wrote:
> Wai Yip Tung wrote:
>
>> I'm not sure what do you mean by index. But you can use len() to get
>> the number of objects in a tuple. e.g.
>>
>>>>> t=(1,2,3)
>>>>> len(t)
>> 3
>>
>>>>> t[2]
>> 3
>>
>
> Lista have an index method that returns the index of the first occurance
> of an element, but tuple doesnt (nor count). Just wondering why.
>
> >>> l= [ 1, 2, 3 ]
> >>> t= ( 1, 2, 3 )
> >>> l.index(2)
> 1
> >>> t.index(2)
> Traceback (most recent call last):
> File "<pyshell#8>", line 1, in ?
> t.index(2)
> AttributeError: 'tuple' object has no attribute 'index'
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