Mailman 3 February 2014 - docs

[issue20241] Bad reference to RFC in document of ipaddress?
by INADA Naoki Feb. 16, 2014

Feb. 16, 2014

New submission from INADA Naoki: http://docs.python.org/3.3/library/ipaddress.html#ipaddress.IPv4Address.is_… > True if the address is unspecified. See RFC 5375 (for IPv4) or RFC 2373 (for IPv6). RFC 5375 is "IPv6 Unicast Address Assignment Considerations". ---------- assignee: docs@python components: Documentation messages: 208027 nosy: docs@python, naoki priority: normal severity: normal status: open title: Bad reference to RFC in document of ipaddress? versions: Python 3.3, Python 3.4 _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue20241> _______________________________________

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[issue12211] Better document math.copysign behavior.
by Mark Dickinson Feb. 16, 2014

Feb. 16, 2014

Mark Dickinson added the comment: Thanks! (And apologies for the nitpicking.) ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by Roundup Robot Feb. 16, 2014

Feb. 16, 2014

Roundup Robot added the comment: New changeset b01f4ed077fa by Andrew Kuchling in branch '3.3': #12211: remove paragraph about NaNs http://hg.python.org/cpython/rev/b01f4ed077fa ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by Mark Dickinson Feb. 16, 2014

Feb. 16, 2014

Mark Dickinson added the comment: > It seems to just copy the sign bit no matter what x and y are. Yep, that's exactly what happens. The sign bit from y just gets blindly transferred to x, with no regard to any meaning of x or y. So it works exactly the same way for zeros, NaNs, infinities, or whatever. ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by A.M. Kuchling Feb. 16, 2014

Feb. 16, 2014

A.M. Kuchling added the comment: Actually ISTM the 'if x is NaN' sentence can also go; it seems to just copy the sign bit no matter what x and y are. >>> from math import * >>> nan = float('nan') >>> neg = -nan >>> copysign(+1, copysign(nan, neg)) -1.0 ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by A.M. Kuchling Feb. 16, 2014

Feb. 16, 2014

A.M. Kuchling added the comment: OK; I'll just drop the 'If y is NaN' sentence. ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by Mark Dickinson Feb. 16, 2014

Feb. 16, 2014

Mark Dickinson added the comment: More examples, showing that `y` is not ignored when `x` is a NaN. >>> result1 = copysign(float('nan'), 1.0) >>> result2 = copysign(float('nan'), -1.0) >>> copysign(1.0, result1) # result1 is a NaN whose sign bit is cleared. 1.0 >>> copysign(1.0, result2) # result2 is a NaN whose sign bit is set. -1.0 ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by Mark Dickinson Feb. 16, 2014

Feb. 16, 2014

Mark Dickinson added the comment: The paragraph about NaNs isn't correct. For example: >>> from math import copysign >>> copysign(1.0, float('nan')) 1.0 >>> copysign(1.0, -float('nan')) -1.0 Though it doesn't really make sense to talk about 'positive' or 'negative' NaNs, a NaN still has a sign bit, and that sign bit is used in the copysign operation. ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by A.M. Kuchling Feb. 16, 2014

Feb. 16, 2014

A.M. Kuchling added the comment: Applied. I added two sentences describing the NaN behaviour. ---------- nosy: +akuchling resolution: -> fixed stage: patch review -> committed/rejected status: open -> closed _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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[issue12211] Better document math.copysign behavior.
by Roundup Robot Feb. 16, 2014

Feb. 16, 2014

Roundup Robot added the comment: New changeset 3ad7725b5013 by Andrew Kuchling in branch '3.3': #12211: clarify math.copysign() documentation and docstring http://hg.python.org/cpython/rev/3ad7725b5013 ---------- nosy: +python-dev _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue12211> _______________________________________

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