iterating through humongously large key lists!!

[Mark blobby Robinson]

Is it is possible to interate through the keys of a dictionary object
without loading the entire key list into memory? I am working with a
situation where I need to interate through a dictionary containly
routinely millions and potentually many millions of keys. Not only is it
painfully slow to generate the list, but it eats into my memory
significantly too. Please tell me there is a better way.

Blobby