Daniel Bünzli wrote:

>> pourtant, je passe bien par un appel a output_value
>> dans un fichier, sans passer par une chaine intermediaire.
> 
> Maybe output_value uses a string internally. Try with a bytecode  
> version of your executable, an exception should be raised (or have a  
> look at the implementaiton of output_value).

I used a bytecode version.

I checked the code of output_value, and it uses an internal
string. So it won't work.

Anyway, I knew I would have to go for a more serious
solution as soon as data get really large. I think of
using something like GDBM.

Thanks for the help.
Sebastien