basic python threading question

[Tom]

I decided to give a thread its own copy of some data.  But I gather that it
is impossible to create a seperate copy of an atomic object (because the
implementation is free to make both names bind to the same object).

This would be a problem for threading, unless all atomic objects are
thead-safe.  Now, all atomic objects appear to me to be immutable.  Are
immutable objects inherently thread-safe in Python (even if the ref count
change)?

Thanks,

Tom.