[issue1537721] csv module: add header row to DictWriter
Changes by florian-rathgeber florian.rathge...@gmail.com: -- nosy: +florian-rathgeber ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Dirkjan Ochtman dirk...@ochtman.nl added the comment: Both the solaris and windows slaves seem to have succeeded this time. -- resolution: - fixed status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Florent Xicluna florent.xicl...@gmail.com added the comment:
according to the buidbots, it hurts some platforms: Windows XP, Windows 7 and
sparc Solaris10
* sparc solaris10
test_writerows (test.test_csv.Test_Csv) ... ok
==
FAIL: test_write_simple_dict (test.test_csv.TestDictFields)
--
Traceback (most recent call last):
File /home2/buildbot/slave/trunk.loewis-sun/build/Lib/test/test_csv.py,
line 607, in test_write_simple_dict
self.assertEqual(fileobj.read(), 10,,abc\r\n)
AssertionError: 'f1,f2,f3\r\n' != '10,,abc\r\n'
--
Ran 84 tests in 17.335s
FAILED (failures=1)
test test_csv failed -- Traceback (most recent call last):
File /home2/buildbot/slave/trunk.loewis-sun/build/Lib/test/test_csv.py,
line 607, in test_write_simple_dict
self.assertEqual(fileobj.read(), 10,,abc\r\n)
AssertionError: 'f1,f2,f3\r\n' != '10,,abc\r\n'
* x86 XP and x86 Windows7
test_csv
test test_csv failed -- Traceback (most recent call last):
File
D:\cygwin\home\db3l\buildarea\trunk.bolen-windows\build\lib\test\test_csv.py,
line 604, in test_write_simple_dict
writer.writerow({f1: 10, f3: abc})
File D:\cygwin\home\db3l\buildarea\trunk.bolen-windows\build\lib\csv.py,
line 148, in writerow
return self.writer.writerow(self._dict_to_list(rowdict))
IOError: [Errno 0] Error
--
nosy: +flox
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[issue1537721] csv module: add header row to DictWriter
Dirkjan Ochtman dirk...@ochtman.nl added the comment: Testing on Windows with this: Index: Lib/test/test_csv.py === --- Lib/test/test_csv.py(revision 78430) +++ Lib/test/test_csv.py(working copy) @@ -9,6 +9,7 @@ import tempfile import csv import gc +import io from test import test_support class Test_Csv(unittest.TestCase): @@ -595,7 +596,7 @@ ### short means there are fewer elements in the row than fieldnames def test_write_simple_dict(self): fd, name = tempfile.mkstemp() -fileobj = os.fdopen(fd, w+b) +fileobj = io.open(fd, 'w+b') try: writer = csv.DictWriter(fileobj, fieldnames = [f1, f2, f3]) writer.writeheader() -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Dirkjan Ochtman dirk...@ochtman.nl added the comment: Committed in r78660 after positive comment from briancurtin re Windows. Hopefully this fixes Solaris, as well. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Dirkjan Ochtman dirk...@ochtman.nl added the comment: Fixed in SVN, r78384. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Changes by Dirkjan Ochtman dirk...@ochtman.nl: -- assignee: - djc resolution: - fixed status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
djc dirk...@ochtman.nl added the comment:
I'd like to commit this, but it would be nice to get a review first:
Index: Lib/csv.py
===
--- Lib/csv.py (revision 76697)
+++ Lib/csv.py (working copy)
@@ -132,6 +132,10 @@
self.extrasaction = extrasaction
self.writer = writer(f, dialect, *args, **kwds)
+def writeheader(self):
+header = dict(zip(self.fieldnames, self.fieldnames))
+self.writerow(header)
+
def _dict_to_list(self, rowdict):
if self.extrasaction == raise:
wrong_fields = [k for k in rowdict if k not in self.fieldnames]
Index: Lib/test/test_csv.py
===
--- Lib/test/test_csv.py(revision 76697)
+++ Lib/test/test_csv.py(working copy)
@@ -598,8 +598,10 @@
fileobj = os.fdopen(fd, w+b)
try:
writer = csv.DictWriter(fileobj, fieldnames = [f1, f2,
f3])
+writer.writeheader()
writer.writerow({f1: 10, f3: abc})
fileobj.seek(0)
+self.assertEqual(fileobj.readline(), f1,f2,f3\r\n)
self.assertEqual(fileobj.read(), 10,,abc\r\n)
finally:
fileobj.close()
(I think I have commit privileges already.)
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[issue1537721] csv module: add header row to DictWriter
Skip Montanaro s...@pobox.com added the comment: I'm sorry, but I don't have time to look at this right now. On the one hand, one person asks for more symmetry. Someone else wants to add a writeheader method. If you want symmetry shouldn't the DictWriter simply write the header without being asked? I'm confused by the various options and feel that someone is going to be disappointed by any solution. For the time being at least I would prefer that the status quo remain in place. S -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
djc dirk...@ochtman.nl added the comment: Skip, I agree that it's hard to decide if we should have the class write the header on __init__(). I figured starting off with a method to make doing it manually is a good start; people can start using that, and if it's deemed useful we can always add the auto-write later. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Antoine Pitrou pit...@free.fr added the comment: We can't change default behaviour because it will break compatibility, so an additional method looks ok to me. -- nosy: +pitrou stage: test needed - patch review versions: +Python 3.2 -Python 3.1 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Skip Montanaro s...@pobox.com added the comment: Antoine We can't change default behaviour because it will break Antoine compatibility, so an additional method looks ok to me. Why can't default behavior be changed? S -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Antoine Pitrou pit...@free.fr added the comment: Le lundi 07 décembre 2009 à 23:42 +, Skip Montanaro a écrit : Skip Montanaro s...@pobox.com added the comment: Antoine We can't change default behaviour because it will break Antoine compatibility, so an additional method looks ok to me. Why can't default behavior be changed? Well, because it will break assumptions about the generated documents? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Skip Montanaro s...@pobox.com added the comment: Antoine We can't change default behaviour because it will break Antoine compatibility, so an additional method looks ok to me. Why can't default behavior be changed? Antoine Well, because it will break assumptions about the generated documents? Isn't the alpha period (2.7 and 3.2 in this case) precisely when an API can change? Skip -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Antoine Pitrou pit...@free.fr added the comment: Isn't the alpha period (2.7 and 3.2 in this case) precisely when an API can change? Well, it can, but only if there are compelling reasons to do so. It should be the exception rather than the rule. The reasons here seem far from compelling, and moreover we can't detect whether the user is expecting the new or the old behaviour. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Skip Montanaro s...@pobox.com added the comment: Isn't the alpha period (2.7 and 3.2 in this case) precisely when an API can change? Antoine Well, it can, but only if there are compelling reasons to do Antoine so. It should be the exception rather than the rule. The Antoine reasons here seem far from compelling, and moreover we can't Antoine detect whether the user is expecting the new or the old Antoine behaviour. Fine. Dirkjan, assuming there are the necessary test cases and documentation changes, feel free to check in your patch and close the ticket. Skip -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Changes by djc dirk...@ochtman.nl: -- nosy: +djc ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Matthew Iversen teh@gmail.com added the comment: Skip, you were arguing in another csv issue on a NamedTupleReader that the Reader and Writer should work in concert together. Certainly, making this default functionality for DictWriter would definitely make it work more in concert with DictReader. A sample process of reading and writing might be: 1. DictReader reads in header names, reads in data 2. Pass in header names to DictWriter on init 3. DictWriter writes out modified data back to csv file (headers get written automatically or with a method call) 4. DictReader can now reader in the csv file automatically again with header names My feeling is, if DictReader can read in head names, why can't DictWriter write them back out again? Shouldn't there be a good amount of symmatry to their function/abilities? My feeling of how to implement this functionality would be to include a new init argument, say 'writeheader'. It's default would be True if you wanted to implement this new feature by default, or False if you wanted to keep it an option so that older scripts relying on the old functionality won't break immmediately. DictWriter would then write the header on the first call to writerow(s), or perhaps also with an explicit call to writeheader() say. I certainly am miffed by the fact that DictWriter cannot produce (normally) a csv file that DictReader can read in automatically. -- nosy: +ivo ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Skip Montanaro s...@pobox.com added the comment: I don't see a patch. Is there some reason that if you need this you can't simply subclass DictWriter? -- nosy: +skip.montanaro ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1537721] csv module: add header row to DictWriter
Changes by Daniel Diniz aja...@gmail.com: -- keywords: +patch stage: - test needed versions: +Python 2.7, Python 3.1 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1537721 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
