SIngleton from __defaults__

[Asaf Las]

On Wednesday, January 22, 2014 6:18:57 PM UTC+2, Chris Angelico wrote:
> On Thu, Jan 23, 2014 at 3:07 AM, Asaf Las <r.... at gmail.com> wrote:
> 
> Why not simply:
> def get_singleton(x = SomeClass()):
>     return x
> Or even:
> singleton = SomeClass()
> ? Neither of the above provides anything above the last one, except
> for late creation.
> 
> ChrisA

Actually need was to have some interface to running independent threads
to give same and once created object always.

For first  - SomeClass's object will be created whenever there will be 
call to get_singleton().
For second, again it is free to create it whenever someone (thread) 
wish. 

Hmmm, use case was to create persistent counter in multithreaded app
accessing single file where incrementing integer is stored.
When my imagination expanded it onto multiprocessing mess i ended up 
using sqlite access to DB in exclusive transaction mode. 
But this was not pythonic :-) 

Asaf