Re: [Python-Dev] Question regarding: Lib/_markupbase.py
Sorry, I just thought that: if '' in rawdata[j:] would do a search, that is, that the implementation of in would just reuse/call the implementation of find and that the position returned would be used as: -1: not in != -1: in which seemed to me like the easy implementation of in. That's why I was wondering why to search twice. Now I realize that it doesn't work the way I thought. Thank you for showing me and sorry for the confusion. Best regards, Guido (another Guido ;-) ) - Ursprüngliche Message - Von: Antoine Pitrou solip...@pitrou.net An: python-dev@python.org CC: Gesendet: 11:22 Dienstag, 12.Februar 2013 Betreff: Re: [Python-Dev] Question regarding: Lib/_markupbase.py Le Mon, 11 Feb 2013 11:02:04 -0800, Guido van Rossum gu...@python.org a écrit : Warning: see http://bugs.python.org/issue17170. Depending on the length of the string being scanned and the probability of finding the specific character, the proposed change could actually be a *pessimization*. OTOH if the character occurs many times, the slice will actually cause O(N**2) behavior. So yes, it depends greatly on the distribution of the input data. That said, the savings are still puny unless you spend your time calling str.find(). Regards Antoine. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/just_another_developer%40yahoo.de ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
Le Mon, 11 Feb 2013 11:02:04 -0800, Guido van Rossum gu...@python.org a écrit : Warning: see http://bugs.python.org/issue17170. Depending on the length of the string being scanned and the probability of finding the specific character, the proposed change could actually be a *pessimization*. OTOH if the character occurs many times, the slice will actually cause O(N**2) behavior. So yes, it depends greatly on the distribution of the input data. That said, the savings are still puny unless you spend your time calling str.find(). Regards Antoine. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
[Python-Dev] Question regarding: Lib/_markupbase.py
Hello all, I was having a look at the file: Lib/_markupbase.py (@ 82151), function: _parse_doctype_element and have seen something that has caught my attention: if '' in rawdata[j:]: return rawdata.find(, j) + 1 Wouldn't it be better to do the following? pos = rawdata.find(, j) if pos != -1: return pos + 1 Otherwise I think we are scanning rawdata[j:] twice. Best regards ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
On Mon, Feb 11, 2013 at 7:16 AM, Developer Developer just_another_develo...@yahoo.de wrote: Wouldn't it be better to do the following? ... Otherwise I think we are scanning rawdata[j:] twice. Yes, that would be better, and avoids a string object creation as well. -Fred -- Fred L. Drake, Jr.fred at fdrake.net A storm broke loose in my mind. --Albert Einstein ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
Same thing in the function: _parse_doctype_attlist: if ) in rawdata[j:]: j = rawdata.find(), j) + 1 else: return -1 I would change it to: pos = rawdata.find(), j) if pos != -1: j = pos + 1 else: return -1 Best regards, Guido - Ursprüngliche Message - Von: Fred Drake f...@fdrake.net An: Developer Developer just_another_develo...@yahoo.de CC: python-dev@python.org python-dev@python.org Gesendet: 15:10 Montag, 11.Februar 2013 Betreff: Re: [Python-Dev] Question regarding: Lib/_markupbase.py On Mon, Feb 11, 2013 at 7:16 AM, Developer Developer just_another_develo...@yahoo.de wrote: Wouldn't it be better to do the following? ... Otherwise I think we are scanning rawdata[j:] twice. Yes, that would be better, and avoids a string object creation as well. -Fred -- Fred L. Drake, Jr. fred at fdrake.net A storm broke loose in my mind. --Albert Einstein ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
If these don't get reported as tracker issues they will probably get lost. --David On Mon, 11 Feb 2013 14:47:00 +, Developer Developer just_another_develo...@yahoo.de wrote: Same thing in the function: _parse_doctype_attlist: if ) in rawdata[j:]:   j = rawdata.find(), j) + 1 else:   return -1 I would change it to: pos = rawdata.find(), j) if pos != -1:   j = pos + 1 else:   return -1 Best regards, Guido - Ursprüngliche Message - Von: Fred Drake f...@fdrake.net An: Developer Developer just_another_develo...@yahoo.de CC: python-dev@python.org python-dev@python.org Gesendet: 15:10 Montag, 11.Februar 2013 Betreff: Re: [Python-Dev] Question regarding: Lib/_markupbase.py On Mon, Feb 11, 2013 at 7:16 AM, Developer Developer just_another_develo...@yahoo.de wrote: Wouldn't it be better to do the following? ... Otherwise I think we are scanning rawdata[j:] twice. Yes, that would be better, and avoids a string object creation as well.  -Fred -- Fred L. Drake, Jr.  fred at fdrake.net A storm broke loose in my mind. --Albert Einstein ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/rdmurray%40bitdance.com ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
Thank you David, I didn't think of the issue tracker. I have just done it. Guido - Ursprüngliche Message - Von: R. David Murray rdmur...@bitdance.com An: Developer Developer just_another_develo...@yahoo.de CC: python-dev@python.org python-dev@python.org Gesendet: 16:59 Montag, 11.Februar 2013 Betreff: Re: [Python-Dev] Question regarding: Lib/_markupbase.py If these don't get reported as tracker issues they will probably get lost. --David On Mon, 11 Feb 2013 14:47:00 +, Developer Developer just_another_develo...@yahoo.de wrote: Same thing in the function: _parse_doctype_attlist: if ) in rawdata[j:]: j = rawdata.find(), j) + 1 else: return -1 I would change it to: pos = rawdata.find(), j) if pos != -1: j = pos + 1 else: return -1 Best regards, Guido - Ursprüngliche Message - Von: Fred Drake f...@fdrake.net An: Developer Developer just_another_develo...@yahoo.de CC: python-dev@python.org python-dev@python.org Gesendet: 15:10 Montag, 11.Februar 2013 Betreff: Re: [Python-Dev] Question regarding: Lib/_markupbase.py On Mon, Feb 11, 2013 at 7:16 AM, Developer Developer just_another_develo...@yahoo.de wrote: Wouldn't it be better to do the following? ... Otherwise I think we are scanning rawdata[j:] twice. Yes, that would be better, and avoids a string object creation as well. -Fred -- Fred L. Drake, Jr. fred at fdrake.net A storm broke loose in my mind. --Albert Einstein ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/rdmurray%40bitdance.com ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
On Mon, Feb 11, 2013 at 12:16:48PM +, Developer Developer just_another_develo...@yahoo.de wrote: I was having a look at the file: Lib/_markupbase.py (@ 82151), function: _parse_doctype_element and have seen something that has caught my attention: if '' in rawdata[j:]: return rawdata.find(, j) + 1 Wouldn't it be better to do the following? pos = rawdata.find(, j) if pos != -1: return pos + 1 Otherwise I think we are scanning rawdata[j:] twice. Is it really a significant optimization? Can you do an experiment and show figures? Oleg. -- Oleg Broytmanhttp://phdru.name/p...@phdru.name Programmers don't die, they just GOSUB without RETURN. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] Question regarding: Lib/_markupbase.py
Warning: see http://bugs.python.org/issue17170. Depending on the length of the string being scanned and the probability of finding the specific character, the proposed change could actually be a *pessimization*. OTOH if the character occurs many times, the slice will actually cause O(N**2) behavior. So yes, it depends greatly on the distribution of the input data. On Mon, Feb 11, 2013 at 4:37 AM, Oleg Broytman p...@phdru.name wrote: On Mon, Feb 11, 2013 at 12:16:48PM +, Developer Developer just_another_develo...@yahoo.de wrote: I was having a look at the file: Lib/_markupbase.py (@ 82151), function: _parse_doctype_element and have seen something that has caught my attention: if '' in rawdata[j:]: return rawdata.find(, j) + 1 Wouldn't it be better to do the following? pos = rawdata.find(, j) if pos != -1: return pos + 1 Otherwise I think we are scanning rawdata[j:] twice. Is it really a significant optimization? Can you do an experiment and show figures? Oleg. -- Oleg Broytmanhttp://phdru.name/p...@phdru.name Programmers don't die, they just GOSUB without RETURN. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/guido%40python.org -- --Guido van Rossum (python.org/~guido) ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
