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Re: iterating over list with one mising value

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  Re: iterating over list with one mising value Dave Angel <d@davea.name> - 2012-02-07 09:46 -0500
    Re: iterating over list with one mising value Rick Johnson <rantingrickjohnson@gmail.com> - 2012-02-07 07:34 -0800
      Re: iterating over list with one mising value Tim Chase <python.list@tim.thechases.com> - 2012-02-07 10:34 -0600

#19960 — Re: iterating over list with one mising value

On 02/07/2012 07:27 AM, Sammy Danso wrote:
> Hello experts,
> I am having trouble accessing the content of my list.
> my list content has 2-pair value with the exception of one which has single value. here is an example  ['a', 1, 'b', 1, 'c', 3, 'd']
>   
> I am unable to iterate through list to access invidual value pairs
>   
> I get an error message saying ' the list should more than 1 value pairs'. I guess because 'd' has no value. How do I solve this problem?
>   
> Your help would be much appreciated.
>   
> Thanks
> Sammy
The real answer is to figure out how it gets into that state.  Is the 
input file invalid?  Or you have a device that sometimes skips one?

But if you're stuck with the data in that list:

If the list is of odd size, truncate it.  Then your loop should not run 
into an uneven pair.

Of course if you actually posted the code, or even the real and complete 
error message, we might be able to make other suggestions.



-- 

DaveA

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#19964

On Feb 7, 8:46 am, Dave Angel <d...@davea.name> wrote:
> On 02/07/2012 07:27 AM, Sammy Danso wrote:> Hello experts,
> > I am having trouble accessing the content of my list.
> > my list content has 2-pair value with the exception of one which has single value. here is an example  ['a', 1, 'b', 1, 'c', 3, 'd']

First you need to explain why you're using a flat list when a number
of other structures would be the better choice; like a list of tuples
or a dict.

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#19966

On 02/07/12 09:34, Rick Johnson wrote:
> On Feb 7, 8:46 am, Dave Angel<d...@davea.name>  wrote:
>> On 02/07/2012 07:27 AM, Sammy Danso wrote:>  Hello experts,
>>> I am having trouble accessing the content of my list. my
>>> list content has 2-pair value with the exception of one
>>> which has single value. here is an example  ['a', 1, 'b',
>>> 1, 'c', 3, 'd']
>
> First you need to explain why you're using a flat list when a
> number of other structures would be the better choice; like a
> list of tuples or a dict.

I'm not sure there's really a need for the OP to explain 
why...perhaps the data comes from an untrusted (or incompetent) 
source and the routine the OP is asking about is to *create* such 
a list-of-tuples or a dict.

The more important question is what the user/app wants to do when 
such a case is encountered:  do they want to ignore the unpaired 
value, or do they want to pad it with a default value?

-tkc

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