Why does python not have a mechanism for data hiding?

[Roy Smith]

In article <slrng4nkq5.ihm.mdw at metalzone.distorted.org.uk>,
 Mark Wooding <mdw at distorted.org.uk> wrote:

>   * Prolog and Erlang distinguish atoms from variables by the case of
>     the first letter; also `_' is magical and is equivalent to a new
>     variable name every time you use it.

Can you explain that in more detail?  A literal reading of what you wrote 
would mean that if you did (assuming this is even legal syntax):

   _ = 1;
   y = _;

the _'s are different variables, which is absurd enough to make me believe 
I just misunderstood you.