Screwing Up looping in Generator

Terry Reedy tjreedy at udel.edu
Mon Jan 2 23:57:52 EST 2017


On 1/3/2017 3:53 PM, Deborah Swanson wrote:

>> I think you're expecting
>>
>>      for file in rootobs
>>
>> to get the next yield for you from rootobs, but unless
>> someone corrects me, I don't think you can expect a 'for'
>> statement to do that. You need to have a 'next' statement
>> inside your for loop to get the next yield from the generator.

As I read this, out of context, it is wrong.  It it very unusual to call next 
on the current iterator (here next(rootobs)), inside a for loop.

> You probably want something like :
>
> for f in rootobs:
>     file = next

This is definitely wrong, as it makes 'find' an alias for the next() function.

>     base = os.path.basename(file.name)

and file.name will be an AttributeError.

-+-
If one wants to iterate through files and lines within files, which I believe I 
saw in this thread, one should have a for loop within a for loop.

--
Terry Jan Reedy



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