Inconsistent viewkeys behaviour

Terry Reedy tjreedy at udel.edu
Mon Apr 28 06:28:48 EDT 2014


On 4/28/2014 2:22 AM, Joshua Landau wrote:
> Is there any reference for this strange behaviour on Python 2:
>
>      >>> set() < dict().viewkeys()
>      Traceback (most recent call last):
>        File "<stdin>", line 1, in <module>
>      TypeError: can only compare to a set
>      >>> dict().viewkeys() > set()
>      False

The left operand determines the result. The manual specifies that < and 
 > do not have to be consistent. But I suspect that when 3.x dict.keys() 
was backported to 2.7.0, no one thought to update set, whereas the 
backported key view code already had the comparison.

-- 
Terry Jan Reedy




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