Tuple question
Colin J. Williams
cjw at sympatico.ca
Thu Sep 2 14:36:40 EDT 2004
Wai Yip Tung wrote:
> 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.
What about:
addresses= list(address)
print addresses
users.append(address)
print users
Colin W.
> 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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