classification
Title: Greek letters not sorted properly
Type: behavior Stage: resolved
Components: Unicode Versions: Python 3.4
process
Status: closed Resolution: duplicate
Dependencies: Superseder: Sorting with locale (strxfrm) does not work properly with Python3 on BSD or OS X
View: 23195
Assigned To: Nosy List: ezio.melotti, pnugues, r.david.murray, vstinner
Priority: normal Keywords:

Created on 2015-01-08 20:54 by pnugues, last changed 2015-01-09 10:04 by pnugues. This issue is now closed.

Messages (6)
msg233686 - (view) Author: Pierre Nugues (pnugues) Date: 2015-01-08 20:54
Greek letters are not properly sorted when a locale is set. I tested a French and a Greek locales. Here is an output obtained from the Python interactive shell available from the python.org home page:

In [22]: a
Out[22]: 
('Ά',
 'Γ',
 'Η',
 'Κ',
 'Ν',
 'Ο',
 'έ',
 'ί',
 'α',
 'β',
 'γ',
 'δ',
 'ε',
 'ζ',
 'ι',
 'κ',
 'λ',
 'μ',
 'ν',
 'ο',
 'ς',
 'τ',
 'φ',
 'χ',
 'ό',
 'ϐ',
 'Ἀ',
 'ῖ')
In [26]: sorted(a, key=locale.strxfrm)
Out[26]: 
['Ἀ',
 'ῖ',
 'α',
 'Ά',
 'β',
 'ϐ',
 'Γ',
 'γ',
 'δ',
 'ε',
 'έ',
 'ζ',
 'Η',
 'ι',
 'ί',
 'Κ',
 'κ',
 'λ',
 'μ',
 'Ν',
 'ν',
 'Ο',
 'ο',
 'ό',
 'ς',
 'τ',
 'φ',
 'χ']

The letter 'ῖ' is wrongly sorted. You can try to sort the same character list with the ICU demonstration to see the correct ordering here: 
http://demo.icu-project.org/icu-bin/locexp?_=el&d_=fr&x=col
msg233688 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-01-08 21:48
This appears to be a duplicate of issue 23196 (the strxfrm issue).
msg233689 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-01-08 21:48
Oops, I meant issue 23195.
msg233726 - (view) Author: Pierre Nugues (pnugues) Date: 2015-01-09 08:09
Hello David,

This is not the same issue as 23195. I tested the Greek letters on your interactive console available at Python.org and this is not related to OS X. The Greek sorting works for all the characters I tested except the ‘ῖ’ character, which is in the extended Greek block. This probably explains why it is not properly collated. ICU sorts the letters properly, including ‘ῖ’.

I think you should restore my original issue post.

Kindest regards,
Pierre
--
Pierre Nugues, Lunds Tekniska Högskola, Institutionen för datavetenskap, Box 118, S-221 00 Lund, Suède.
Tél. (0046) 46 222 96 40, http://cs.lth.se/pierre_nugues
Visiteurs: Lunds Tekniska Högskola, E-huset, rum 4134A, Ole Römers väg 3, S-223 63 Lund.
Mon livre/My book: http://ilppp.cs.lth.se (2nd edition, 2014)

> Le 8 janv. 2015 à 22:48, R. David Murray <report@bugs.python.org> a écrit :
> 
> 
> R. David Murray added the comment:
> 
> Oops, I meant issue 23195.
> 
> ----------
> superseder: Greek letters not sorted properly -> Sorting with locale (strxfrm) does not work properly with Python3 on Macos
> 
> _______________________________________
> Python tracker <report@bugs.python.org>
> <http://bugs.python.org/issue23196>
> _______________________________________
msg233734 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2015-01-09 08:43
Which order do you expect? What is your OS? Result on Linux (Fedora 21) with the french UTF-8 locale.

>>> locale.setlocale(locale.LC_ALL, '')
'fr_FR.utf8'
>>> locale.getlocale(locale.LC_COLLATE)
('fr_FR', 'UTF-8')
>>> sorted(x)
['Ά', 'Γ', 'Η', 'Κ', 'Ν', 'Ο', 'έ', 'ί', 'α', 'β', 'γ', 'δ', 'ε', 'ζ', 'ι', 'κ', 'λ', 'μ', 'ν', 'ο', 'ς', 'τ', 'φ', 'χ', 'ό', 'ϐ', 'Ἀ', 'ῖ']
>>> sorted(x, key=locale.strxfrm)
['Ἀ', 'ῖ', 'α', 'Ά', 'β', 'ϐ', 'Γ', 'γ', 'δ', 'ε', 'έ', 'ζ', 'Η', 'ι', 'ί', 'Κ', 'κ', 'λ', 'μ', 'Ν', 'ν', 'Ο', 'ο', 'ό', 'ς', 'τ', 'φ', 'χ']

I don't speak greek, I don't know which order is expected.

Anyway, as explained in the issue #23195, Python doesn't implement locale.strxfrm(): it just exposes the system functions. On Linux, locales are implemented in the GNU C library ("libc") for example.

So I don't see what should be done to "fix" this issue. We are not going to implement locales in Python, use an external library like ICU if you want "better" locales and have a better control on locales.
msg233741 - (view) Author: Pierre Nugues (pnugues) Date: 2015-01-09 10:04
Hello Victor,

Thank you for your prompt answer.

> Which order do you expect? What is your OS? Result on Linux (Fedora 21) with the french UTF-8 locale.
You can try this ICU demo http://demo.icu-project.org/icu-bin/locexp?_=el&d_=fr&x=col and paste the list:

Ά
Γ
Η
Κ
Ν
Ο
έ
ί
α
β
γ
δ
ε
ζ
ι
κ
λ
μ
ν
ο
ς
τ
φ
χ
ό
ϐ
Ἀ
ῖ

You will get the same ordering as with Fedora, except the ῖ. It is a variant of i (corresponding to the letter i in Latin character). It should be sorted as an i and not just after Ἀ (the uppercase form of alpha) and before α (alpha).

> 
>>>> locale.setlocale(locale.LC_ALL, '')
> 'fr_FR.utf8'
>>>> locale.getlocale(locale.LC_COLLATE)
> ('fr_FR', 'UTF-8')
>>>> sorted(x)
> ['Ά', 'Γ', 'Η', 'Κ', 'Ν', 'Ο', 'έ', 'ί', 'α', 'β', 'γ', 'δ', 'ε', 'ζ', 'ι', 'κ', 'λ', 'μ', 'ν', 'ο', 'ς', 'τ', 'φ', 'χ', 'ό', 'ϐ', 'Ἀ', 'ῖ']
>>>> sorted(x, key=locale.strxfrm)
> ['Ἀ', 'ῖ', 'α', 'Ά', 'β', 'ϐ', 'Γ', 'γ', 'δ', 'ε', 'έ', 'ζ', 'Η', 'ι', 'ί', 'Κ', 'κ', 'λ', 'μ', 'Ν', 'ν', 'Ο', 'ο', 'ό', 'ς', 'τ', 'φ', 'χ']
> 
> I don't speak greek, I don't know which order is expected.
> 
> Anyway, as explained in the issue #23195, Python doesn't implement locale.strxfrm(): it just exposes the system functions. On Linux, locales are implemented in the GNU C library ("libc") for example.
> 
> So I don't see what should be done to "fix" this issue. We are not going to implement locales in Python, use an external library like ICU if you want "better" locales and have a better control on locales.
May be this would be a good idea…

Kindest regards,
Pierre
--
Pierre Nugues, Lunds Tekniska Högskola, Institutionen för datavetenskap, Box 118, S-221 00 Lund, Suède.
Tél. (0046) 46 222 96 40, http://cs.lth.se/pierre_nugues
Visiteurs: Lunds Tekniska Högskola, E-huset, rum 4134A, Ole Römers väg 3, S-223 63 Lund.
Mon livre/My book: http://ilppp.cs.lth.se (2nd edition, 2014)
History
Date User Action Args
2015-01-09 10:04:04pnuguessetmessages: + msg233741
2015-01-09 08:43:55vstinnersetmessages: + msg233734
2015-01-09 08:09:22pnuguessetmessages: + msg233726
2015-01-08 21:48:27r.david.murraysetsuperseder: Greek letters not sorted properly -> Sorting with locale (strxfrm) does not work properly with Python3 on BSD or OS X
messages: + msg233689
2015-01-08 21:48:27r.david.murrayunlinkissue23196 superseder
2015-01-08 21:48:04r.david.murraysetstatus: open -> closed

superseder: Greek letters not sorted properly

nosy: + r.david.murray
messages: + msg233688
resolution: duplicate
stage: resolved
2015-01-08 21:48:04r.david.murraylinkissue23196 superseder
2015-01-08 20:54:42pnuguescreate