[Python-Dev] Retrieve an arbitrary element from a set withoutremoving it

[Georg Brandl]

Steven D'Aprano schrieb:
> On Wed, 28 Oct 2009 04:47:59 am Raymond Hettinger wrote:
> 
>> A dict.get() can be meaningfully used in a loop (because the key can
>> vary). A set.get() returns the same value over and over again
>> (because there is no key).
> 
> I don't believe anyone has requested those semantics. The suggested 
> semantics for set.get() with no arguments, as I understand them, are:
> 
> (1) it will only fail if the set is empty;
> 
> (2) it should be efficient;
> 
> (3) if you call it repeatedly on a set without modifying the set, you 
> will cycle through each element in turn in some unspecified arbitrary 
> order.

I don't like this.  It gives a set object a hidden state, something that
AFAICS no other builtin has.  Iterating over an iterable is what iterators
are for.

Georg

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