Henry Steigerwaldt wrote:

> To All:
> 
> Can anyone tell me how to use the tell( ) function when 
> accessing data on the Web?
> 
> I know how to use it when reading a file from the hard drive,
> but I get an error using it after reading text via the Web and
> then trying to use it on that particular "file object."
> 

I believe that the file-like object that urllib provides does not 
support tell(), nor seek().  This is due to underlying limitations of 
using a data stream as a file -- there's no truly meaningful concept of 
"position" in a data stream.  Similarly, seek() and tell() don't -- 
can't -- work on sockets.

> I guess I could save the data to a file,
> then open the file and read it, THEN use the tell ( ) (and for that
> matter the seek( ) ) function like I am accustomed to doing
> successfully in the past. But I should be able to use it as is on the
> file object.
> 

If you really need seek() and tell(), then you'll have to save the data 
to a disk file.  Remember, urllib and such don't provide an actual file 
object, just a "file-like" object.  This is one of the relatively few 
ways that it doesn't (can't) completely mimic a true file object.  (Of 
all file methods, seek() and tell() are the ones most often left 
unimplemented in file-like objects, most often because they hold no 
meaning to the form of the underlying data that the file-like object is 
wrapping.)

Jeff Shannon
Technician/Programmer
Credit International





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