Message 169398 - Python tracker

Message169398

Author	skrah
Recipients	Arfrever, christian.heimes, georg.brandl, loewis, mark.dickinson, meador.inge, ncoghlan, pitrou, skrah, vstinner
Date	2012-08-29.17:07:08
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1346260029.19.0.320505643782.issue15814@psf.upfronthosting.co.za>
In-reply-to

Content
The new PEP-3118 equality definition from #15573 that is based on element-wise comparisons breaks the equality-hash invariant: >>> from _testbuffer import ndarray >>> x = ndarray([1,2,3], shape=[3], format='f') >>> y = ndarray([1,2,3], shape=[3], format='B') >>> a = memoryview(x) >>> b = memoryview(y) >>> a == b True >>> hash(a) == hash(b) False >>>

Content

The new PEP-3118 equality definition from #15573 that is based
on element-wise comparisons breaks the equality-hash invariant:

>>> from _testbuffer import ndarray
>>> x = ndarray([1,2,3], shape=[3], format='f')
>>> y = ndarray([1,2,3], shape=[3], format='B')
>>> a = memoryview(x)
>>> b = memoryview(y)
>>> a == b
True
>>> hash(a) == hash(b)
False
>>>

History
Date	User	Action	Args
2012-08-29 17:07:09	skrah	set	recipients: + skrah, loewis, georg.brandl, mark.dickinson, ncoghlan, pitrou, vstinner, christian.heimes, Arfrever, meador.inge
2012-08-29 17:07:09	skrah	set	messageid: <1346260029.19.0.320505643782.issue15814@psf.upfronthosting.co.za>
2012-08-29 17:07:08	skrah	link	issue15814 messages
2012-08-29 17:07:08	skrah	create