Mailman 3 March 2011 - docs

[issue9802] Document 'stability' of builtin min() and max()
by Matthew Woodcraft 04 Mar '11

04 Mar '11

New submission from Matthew Woodcraft <matthew(a)woodcraft.me.uk>: In CPython, the builtin max() and min() have the property that if there are items with equal keys, the first item is returned. From a quick look at their source, I think this is true for Jython and IronPython too. I propose making this a documented guarantee. On Python-dev, Raymond Hettinger said: << That seems like a reasonable request. This behavior has been around for a very long time is unlikely to change. Elsewhere, we've made efforts to document sort stability (i.e. sorted(), heapq.nlargest(), heapq.nsmallest, merge(), etc). >> (<http://mail.python.org/pipermail/python-dev/2010-September/103543.html>) I'm attaching a patch with a concrete suggestion for a change to functions.rst, modelled on the documentation of heapq.nlargest(). ---------- assignee: docs@python components: Documentation files: maxmin.patch keywords: patch messages: 115892 nosy: docs@python, mattheww priority: normal severity: normal status: open title: Document 'stability' of builtin min() and max() type: feature request Added file: http://bugs.python.org/file18802/maxmin.patch _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue9802> _______________________________________

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chaos
by Colin Reveley 04 Mar '11

04 Mar '11

here: http://docs.python.org/library/turtle.html#demo-scripts you say that chaotic behavior "proves that you cannot trust a computer's computations" well, the opposite is the case. it proves you can trust computations absolutely. the computations are deterministic. they are correct. that's how the lorenz attractor was discovered. you do need to know what a computer does (and to what) when it computes, and what it doesn't, and how to interpret it. it's misleading to say that computation is untrustworthy. computation is a particular thing, that's all. it might seem pedantic but I think it's a much more interesting and important thing for a student to think about than "untrustworthy". which is just false anyway. as you know I'm sure. I'm not trying to be patronising.

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[issue11368] Document why xml.etree.ElementTree.Element has no reference to parent
by Georg Brandl 04 Mar '11

04 Mar '11

Changes by Georg Brandl <georg(a)python.org>: ---------- title: xml.etree.ElementTree.Element should have a reference to parent -> Document why xml.etree.ElementTree.Element has no reference to parent _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue11368> _______________________________________

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[issue11368] xml.etree.ElementTree.Element should have a reference to parent
by Georg Brandl 04 Mar '11

04 Mar '11

Changes by Georg Brandl <georg(a)python.org>: ---------- assignee: -> docs@python components: +Documentation -XML nosy: +docs@python _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue11368> _______________________________________

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plistlib doc
by David Cotter 03 Mar '11

03 Mar '11

http://docs.python.org/library/plistlib.html does not list all the available methods of each new class please document: for example: what are the methods of "Dict" ? 'clear', 'copy', 'fromkeys', 'get', 'has_key', 'items', 'iteritems', 'iterkeys', 'itervalues', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'values' these are not documented and what about all the other classes? ------------------------------------------------------------------------------ David M. Cotter mailto:david.cotter@adobe.com Interface Surgeon, After Effects http://www.adobe.com/aftereffects/ Adobe Systems, Inc. (206) 675-7437

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Documentation bug in 25.2.3.5. Option Flags and Directives
by David Bronke 03 Mar '11

03 Mar '11

In section 25.2.3.5, "Option Flags and Directives" at http://docs.python.org/dev/library/doctest.html<http://docs.python.org/dev/library/doctest.html?highlight=doctest#doctest>, the code examples for doctest directives don't actually show the directives themselves; they seem to be hidden.

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[issue11372] Remove xrange from argparse docs
by Ross Lagerwall 03 Mar '11

03 Mar '11

New submission from Ross Lagerwall <rosslagerwall(a)gmail.com>: As the title says, this patch replaces xrange with range for the 3.3 docs. ---------- assignee: docs@python components: Documentation files: doc.patch keywords: patch messages: 129876 nosy: docs@python, rosslagerwall priority: normal severity: normal status: open title: Remove xrange from argparse docs versions: Python 3.3 Added file: http://bugs.python.org/file20974/doc.patch _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue11372> _______________________________________

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tutorial example bug: filter function
by Schaffer, Steve (317J) 02 Mar '11

02 Mar '11

There is a bug in the first example (or at least bug in the description of it) at: http://docs.python.org/tutorial/datastructures.html#functional-programming-… The prose introducing the example reads: "For example, to compute primes up to 25:" And then the actual example shows output: "[5, 7, 11, 13, 17, 19, 23]" The actual list of prime numbers less than 25 should include both 2 and 3: "[2, 3, 5, 7, 11, 13, 17, 19, 23]" The filter f(x) in the example actually tests for multiples of 2 or 3, it does not test for compositeness. I think the example of filter functions would be demonstrated adequately with a simpler filter def f(x): return x % 2 == 0 filter(f, range(1,10)) With the corresponding description For example, to find the even number up to 10:

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Regarding standard Hex32 bit conversion
by GV, Krishnan (GE Transportation, Non-GE) 02 Mar '11

02 Mar '11

Hi, I have been learning python for the last few months. I was not able to find a function for conversion from a 32-bit Hexadecimal Representation To Decimal Floating-Point. The one included in the library is really tough to use. Hence I have written my own. Kindly go through and acknowledge if u like it or otherwise. def hexconvert32(str_rcv): #string received :str_rcv str_rcv='0x'+str_rcv #appending 0x to it str_bin=bin(int(str_rcv,16)) #converting to binary k=[] #initializing reverse list k for i in range(len(str_bin)-1,-1,-1): k.append(str_bin[i]) k.pop() # popping the '0' k.pop() #popping the 'b' for i in range(len(k),33,1): #padding with 0 k.append('0') sign_bit=k.pop() #popping the sign bit expo='' sini='' for exp in range(30,22,-1): #removing exponent part expo= expo + k[exp] for sin in range(22,-1,-1): #removing significand part sini= sini + k[sin] h=[] dval=0 for i in range(1, len(sini),1): #finding the decimal value of significand dval =dval + (int(sini[i-1])*pow(2,(-1)*(i))) dval=dval+1 # adding 1 to the decimal dval #from here on we are looking at cases for each value. Detailed equations and explanations @ http://www.psc.edu/general/software/packages/ieee/ieee.php if int(expo,2)<255 and int(expo,2)>0 : v=(pow(-1,int(sign_bit,2)))*(pow(2,int(expo,2)-127))*(dval) return v elif int(expo,2)==0 and int(sini,2)!=0: v=(pow(-1,int(sign_bit,2)))*(pow(2,-126))*(dval-1) print v , 'unnormalized value' return 0 elif int(expo,2)==255 and int(sini,2)!=0: print 'Not a Number' return 0 elif int(expo,2)==0 and int(sini,2)==0 and int(sign_bit,2)==1: print '- infinity' return 0 elif int(expo,2)==0 and int(sini,2)==0 and int(sign_bit,2)==0: print 'infinity' return 0 else: print 'error' return 0 Thanks and Regards!! Krishnan G.V

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[issue11366] xml.etree.ElementTree.Element: docs should mention immediate subelement
by anatoly techtonik 02 Mar '11

02 Mar '11

anatoly techtonik <techtonik(a)gmail.com> added the comment: See also http://diveintopython3.org/xml.html#xml-find ---------- _______________________________________ Python tracker <report(a)bugs.python.org> <http://bugs.python.org/issue11366> _______________________________________

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