shelve file name extention

[Monu]

Hi All,
When I am using shelve on my local machine it generates the db file as
given filename. But in another machine it's generating <filename>.dat
and .dir.
can anyone tell me how can I force sheve module to write the db in
<filename>.dir and <filename>.dat, instead of <filename>? Do I have to
install a specific version of the python?

Thanks...
Monu