From tom.brown.code at gmail.com Sun Oct 19 01:15:01 2008 From: tom.brown.code at gmail.com (Tom Brown) Date: Sat, 18 Oct 2008 16:15:01 -0700 Subject: [Csv] skipfinalspace Message-ID: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> Hello python csv gurus! I use the csv module pretty heavily in http://code.google.com/p/googletransitdatafeed/source/browse/trunk/python/transitfeed.pyand someone recently complained that it doesn't handle white space before and after fields. I can fix this skipinitialspace and a little post-processing to remove trailing whitespace but thought it would be nice to add skipifinalspace to the csv module. We have 476 feeds generated by different tools (plugins to various proprietary software, Python's csv, by hand, Excel, ...). Of these 9 have a space after fields in the header and 22 have spaces before fields in the header. I downloaded the 2.6 source tar ball, but is it too late for new features to get into versions <3? How would you feel about adding the following tests to Lib/test/test_csv.py and getting them to pass? Also http://www.python.org/doc/2.5.2/lib/csv-fmt-params.html says "*skipinitialspace *When True, whitespace immediately following the delimiter is ignored." but my tests show whitespace at the start of any field is ignored, including the first field. Thanks, Tom class TestDialectOption(TestCsvBase): @staticmethod def makeDialect(dct): name = "dialect-%d" % (hash(tuple(dct.items()))) return type(name, (csv.excel, object), dct)() def test_no_skip(self): self.dialect = self.makeDialect({}) self.readerAssertEqual(' foo,bar', [[' foo', 'bar']]) self.readerAssertEqual('foo, bar', [['foo', ' bar']]) self.readerAssertEqual(' foo, bar', [[' foo', ' bar']]) self.readerAssertEqual(' foo , bar', [[' foo ', ' bar']]) self.readerAssertEqual(' foo , bar ', [[' foo ', ' bar ']]) def test_skip_initial(self): self.dialect = self.makeDialect({"skipinitialspace": True}) self.readerAssertEqual(' foo,bar', [['foo', 'bar']]) self.readerAssertEqual('foo, bar', [['foo', 'bar']]) self.readerAssertEqual(' foo, bar', [['foo', 'bar']]) self.readerAssertEqual(' foo , bar', [['foo ', 'bar']]) self.readerAssertEqual(' foo , bar ', [['foo ', 'bar ']]) def test_skip_final(self): self.dialect = self.makeDialect({"skipfinalspace": True}) self.readerAssertEqual(' foo,bar', [[' foo', 'bar']]) self.readerAssertEqual('foo, bar', [['foo', ' bar']]) self.readerAssertEqual(' foo, bar', [[' foo', ' bar']]) self.readerAssertEqual(' foo , bar', [[' foo', ' bar']]) self.readerAssertEqual(' foo , bar ', [[' foo', ' bar']]) def test_skip_both(self): self.dialect = self.makeDialect({"skipinitialspace": True, "skipfinalspace": True}) self.readerAssertEqual(' foo,bar', [['foo', 'bar']]) self.readerAssertEqual('foo, bar', [['foo', 'bar']]) self.readerAssertEqual(' foo, bar', [['foo', 'bar']]) self.readerAssertEqual(' foo , bar', [['foo', 'bar']]) self.readerAssertEqual(' foo , bar ', [['foo', 'bar']]) -------------- next part -------------- An HTML attachment was scrubbed... URL: From andrewm at object-craft.com.au Mon Oct 20 01:46:04 2008 From: andrewm at object-craft.com.au (Andrew McNamara) Date: Mon, 20 Oct 2008 10:46:04 +1100 Subject: [Csv] skipfinalspace In-Reply-To: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> References: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> Message-ID: <20081019234604.B70DB59C001@longblack.object-craft.com.au> >I downloaded the 2.6 source tar ball, but is it too late for new features to >get into versions <3? Yep. >How would you feel about adding the following tests to Lib/test/test_csv.py >and getting them to pass? > >Also http://www.python.org/doc/2.5.2/lib/csv-fmt-params.html says >"*skipinitialspace *When True, whitespace immediately following the >delimiter is ignored." >but my tests show whitespace at the start of any field is ignored, including >the first field. I suspect (but I haven't checked) that it means "after the delimiter and before any quoted field (or some variation on that). All of the "dialect" parameters are there to allow parsing of a specific common form of CSV file. Because there is no formal definition of the format, the module simply aims to parse (and produce the same result) as common applications such as Excel and Access. Changing the behaviour in any non-backwards compatible way is sure to get screams of anguish from many users. Even when the behaviour appears to be a bug, you can be sure people are counting on it working like that. BTW, this discussion probably should move to python-dev. -- Andrew McNamara, Senior Developer, Object Craft http://www.object-craft.com.au/ From tom.brown.code at gmail.com Mon Oct 20 07:06:51 2008 From: tom.brown.code at gmail.com (Tom Brown) Date: Sun, 19 Oct 2008 22:06:51 -0700 Subject: [Csv] skipfinalspace In-Reply-To: <9789242b0810192154w557dedd8seba60c3deb168f12@mail.gmail.com> References: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> <20081019234604.B70DB59C001@longblack.object-craft.com.au> <9789242b0810192154w557dedd8seba60c3deb168f12@mail.gmail.com> Message-ID: <9789242b0810192206n318fb7cao8bba9341695af053@mail.gmail.com> (Continuing thread started at http://mail.python.org/pipermail/csv/2008-October/000688.html) On Sun, Oct 19, 2008 at 16:46, Andrew McNamara wrote: > >I downloaded the 2.6 source tar ball, but is it too late for new features > to > >get into versions <3? > > Yep. > > >How would you feel about adding the following tests to > Lib/test/test_csv.py > >and getting them to pass? > > > >Also http://www.python.org/doc/2.5.2/lib/csv-fmt-params.html says > >"*skipinitialspace *When True, whitespace immediately following the > >delimiter is ignored." > >but my tests show whitespace at the start of any field is ignored, > including > >the first field. > > I suspect (but I haven't checked) that it means "after the delimiter and > before any quoted field (or some variation on that). I agree that whitespace after the delimiter and before any quoted field is skipped. Also whitespace after the start of the line and before any quoted field is skipped. > > > All of the "dialect" parameters are there to allow parsing of a specific > common form of CSV file. Because there is no formal definition of the > format, the module simply aims to parse (and produce the same result) > as common applications such as Excel and Access. Changing the behaviour > in any non-backwards compatible way is sure to get screams of anguish > from many users. Even when the behaviour appears to be a bug, you can > be sure people are counting on it working like that. skipinitialspace defaults to false and by the same logic skipfinalspace should default to false to preserve compatibility with the csv module in 2.6. On the other hand, the switch to version 3 is as good a time as any to break backwards compatibility to adopt something that works better for new users. Based on my experience parsing several hundred csv generated by many different people I think it would be nice to at least have a dialect that is excel + skipinitialspace=True + skipfinalspace=True. > > BTW, this discussion probably should move to python-dev. > > -- > Andrew McNamara, Senior Developer, Object Craft > http://www.object-craft.com.au/ > -------------- next part -------------- An HTML attachment was scrubbed... URL: From sjmachin at lexicon.net Mon Oct 20 09:48:10 2008 From: sjmachin at lexicon.net (John Machin) Date: Mon, 20 Oct 2008 18:48:10 +1100 Subject: [Csv] skipfinalspace In-Reply-To: <9789242b0810192206n318fb7cao8bba9341695af053@mail.gmail.com> References: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> <20081019234604.B70DB59C001@longblack.object-craft.com.au> <9789242b0810192154w557dedd8seba60c3deb168f12@mail.gmail.com> <9789242b0810192206n318fb7cao8bba9341695af053@mail.gmail.com> Message-ID: <48FC37BA.20303@lexicon.net> Tom Brown wrote: > (Continuing thread started at > http://mail.python.org/pipermail/csv/2008-October/000688.html) > > On Sun, Oct 19, 2008 at 16:46, Andrew McNamara > > wrote: > > >I downloaded the 2.6 source tar ball, but is it too late for new > features to > >get into versions <3? > > Yep. > > >How would you feel about adding the following tests to > Lib/test/test_csv.py > >and getting them to pass? > > > >Also http://www.python.org/doc/2.5.2/lib/csv-fmt-params.html says > >"*skipinitialspace *When True, whitespace immediately following the > >delimiter is ignored." > >but my tests show whitespace at the start of any field is ignored, > including > >the first field. > > I suspect (but I haven't checked) that it means "after the delimiter and > before any quoted field (or some variation on that). > > I agree that whitespace after the delimiter and before any quoted field > is skipped. Also whitespace after the start of the line and before any > quoted field is skipped. > All of the "dialect" parameters are there to allow parsing of a specific > common form of CSV file. Because there is no formal definition of the > format, the module simply aims to parse (and produce the same result) > as common applications such as Excel and Access. Changing the behaviour > in any non-backwards compatible way is sure to get screams of anguish > from many users. Even when the behaviour appears to be a bug, you can > be sure people are counting on it working like that. > > > skipinitialspace defaults to false and by the same logic skipfinalspace > should default to false to preserve compatibility with the csv module in > 2.6. On the other hand, the switch to version 3 is as good a time as any > to break backwards compatibility to adopt something that works better > for new users. Read Andrew's lips: They don't want "better", they want "the same as MS". > Based on my experience parsing several hundred csv generated by many > different people I think it would be nice to at least have a dialect > that is excel + skipinitialspace=True + skipfinalspace=True. Based on my experience extracting data from innumerable csv files (and infinite varieties thereof), spreadsheet files, and database tables, in 99.99% of cases one should automatically apply the following transformations to each text field: * strip leading whitespace * strip trailing whitespace * replace embedded runs of whitespace by a single space and one needs to ensure that the definition of whitespace includes the no-break space (NBSP) character. As this "space normalisation" is needed for all input sources, the csv module is IMHO the wrong place to put it. A string method would be a better idea. Cheers, John From tom.brown.code at gmail.com Tue Oct 21 09:21:50 2008 From: tom.brown.code at gmail.com (Tom Brown) Date: Tue, 21 Oct 2008 00:21:50 -0700 Subject: [Csv] skipfinalspace In-Reply-To: <9789242b0810210021re3dd771o3a7a19f177d8be41@mail.gmail.com> References: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> <20081019234604.B70DB59C001@longblack.object-craft.com.au> <9789242b0810192154w557dedd8seba60c3deb168f12@mail.gmail.com> <9789242b0810192206n318fb7cao8bba9341695af053@mail.gmail.com> <48FC37BA.20303@lexicon.net> <9789242b0810210021re3dd771o3a7a19f177d8be41@mail.gmail.com> Message-ID: <9789242b0810210021v344a6d86sec0859633a639724@mail.gmail.com> On Mon, Oct 20, 2008 at 00:48, John Machin wrote: > Tom Brown wrote: > >> (Continuing thread started at >> http://mail.python.org/pipermail/csv/2008-October/000688.html) >> >> On Sun, Oct 19, 2008 at 16:46, Andrew McNamara < >> andrewm at object-craft.com.au > wrote: >> >> >I downloaded the 2.6 source tar ball, but is it too late for new >> features to >> >get into versions <3? >> >> Yep. >> >> >How would you feel about adding the following tests to >> Lib/test/test_csv.py >> >and getting them to pass? >> > >> >Also http://www.python.org/doc/2.5.2/lib/csv-fmt-params.html says >> >"*skipinitialspace *When True, whitespace immediately following the >> >delimiter is ignored." >> >but my tests show whitespace at the start of any field is ignored, >> including >> >the first field. >> >> I suspect (but I haven't checked) that it means "after the delimiter >> and >> before any quoted field (or some variation on that). >> >> I agree that whitespace after the delimiter and before any quoted field is >> skipped. Also whitespace after the start of the line and before any quoted >> field is skipped. >> > > All of the "dialect" parameters are there to allow parsing of a >> specific >> common form of CSV file. Because there is no formal definition of the >> format, the module simply aims to parse (and produce the same result) >> as common applications such as Excel and Access. Changing the behaviour >> in any non-backwards compatible way is sure to get screams of anguish >> from many users. Even when the behaviour appears to be a bug, you can >> be sure people are counting on it working like that. >> >> >> skipinitialspace defaults to false and by the same logic skipfinalspace >> should default to false to preserve compatibility with the csv module in >> 2.6. On the other hand, the switch to version 3 is as good a time as any to >> break backwards compatibility to adopt something that works better for new >> users. >> > > Read Andrew's lips: They don't want "better", they want "the same as MS". okay. > > > Based on my experience parsing several hundred csv generated by many >> different people I think it would be nice to at least have a dialect that is >> excel + skipinitialspace=True + skipfinalspace=True. >> > > Based on my experience extracting data from innumerable csv files (and > infinite varieties thereof), Wow, that is a _lot_ of files :-P spreadsheet files, and database tables, in 99.99% of cases one should > automatically apply the following transformations to each text field: > * strip leading whitespace > * strip trailing whitespace > * replace embedded runs of whitespace by a single space > and one needs to ensure that the definition of whitespace includes the > no-break space (NBSP) character. > > As this "space normalisation" is needed for all input sources, the csv > module is IMHO the wrong place to put it. A string method would be a better > idea. I agree that strip() and something like re.sub(r"\s+", " " are handy. If 99.99% percent of csv readers should be applying these fixes to every field perhaps there should be easy-to-enable option to apply it. Why force almost everyone to discover they need the transformations and put a line of code around csv reader? -------------- next part -------------- An HTML attachment was scrubbed... URL: From magnus at hetland.org Tue Oct 21 13:03:41 2008 From: magnus at hetland.org (Magnus Lie Hetland) Date: Tue, 21 Oct 2008 13:03:41 +0200 Subject: [Csv] skipfinalspace In-Reply-To: <48FC37BA.20303@lexicon.net> References: <9789242b0810181615w5b1325c6h2149990854cff83d@mail.gmail.com> <20081019234604.B70DB59C001@longblack.object-craft.com.au> <9789242b0810192154w557dedd8seba60c3deb168f12@mail.gmail.com> <9789242b0810192206n318fb7cao8bba9341695af053@mail.gmail.com> <48FC37BA.20303@lexicon.net> Message-ID: <87772659-8D79-4CEF-BF7A-E633A38D4A25@hetland.org> On Oct 20, 2008, at 09:48, John Machin wrote: > Based on my experience extracting data from innumerable csv files > (and infinite varieties thereof), spreadsheet files, and database > tables, in 99.99% of cases one should automatically apply the > following transformations to each text field: > * strip leading whitespace > * strip trailing whitespace > * replace embedded runs of whitespace by a single space > and one needs to ensure that the definition of whitespace includes > the no-break space (NBSP) character. > > As this "space normalisation" is needed for all input sources, the > csv module is IMHO the wrong place to put it. A string method would > be a better idea. Hm. It seems quite familiar, somehow... You could certainly do the following (for each field)... " ".join(field.split()) ... but I seem to recall running across something that did this? (Maybe I'm confusing it with some other issue, with the string.capwords function versis str.title :) -- Magnus Lie Hetland http://hetland.org