From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52614) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVEDg-0005Nb-F3 for qemu-devel@nongnu.org; Tue, 19 Jun 2018 06:50:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fVEDc-0006ho-Dj for qemu-devel@nongnu.org; Tue, 19 Jun 2018 06:50:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61387) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fVEDc-0006hf-2z for qemu-devel@nongnu.org; Tue, 19 Jun 2018 06:50:36 -0400 Date: Tue, 19 Jun 2018 07:50:32 -0300 From: Eduardo Habkost Message-ID: <20180619105032.GO7451@localhost.localdomain> References: <20180618175958.29073-1-armbru@redhat.com> <20180618175958.29073-2-armbru@redhat.com> <20180618213526.GJ24764@localhost.localdomain> <87tvpzz3wn.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87tvpzz3wn.fsf@dusky.pond.sub.org> Subject: Re: [Qemu-devel] [PATCH v4 1/2] qapi: Open files with encoding='utf-8' List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: tamiko@43-1.org, qemu-devel@nongnu.org, arfrever.fta@gmail.com On Tue, Jun 19, 2018 at 08:28:08AM +0200, Markus Armbruster wrote: > Eduardo Habkost writes: > > > On Mon, Jun 18, 2018 at 07:59:57PM +0200, Markus Armbruster wrote: > >> Python 2 happily reads UTF-8 files in text mode, but Python 3 requires > >> either UTF-8 locale or an explicit encoding passed to open(). Commit > >> d4e5ec877ca fixed this by setting the en_US.UTF-8 locale. Falls apart > >> when the locale isn't be available. > >> > >> Matthias Maier and Arfrever Frehtes Taifersar Arahesis proposed to use > >> binary mode instead, with manual conversion from bytes to str. Works, > >> but opening with an explicit encoding is simpler, so do that. > >> > >> Since Python 2's open() doesn't support the encoding parameter, we > >> need to suppress it with a version check. > >> > >> Reported-by: Arfrever Frehtes Taifersar Arahesis > >> Reported-by: Matthias Maier > >> Signed-off-by: Markus Armbruster > >> --- > >> scripts/qapi/common.py | 17 ++++++++++++++--- > >> 1 file changed, 14 insertions(+), 3 deletions(-) > >> > >> diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py > >> index 2462fc0291..832f11438a 100644 > >> --- a/scripts/qapi/common.py > >> +++ b/scripts/qapi/common.py > >> @@ -16,6 +16,7 @@ import errno > >> import os > >> import re > >> import string > >> +import sys > >> from collections import OrderedDict > >> > >> builtin_types = { > >> @@ -340,7 +341,10 @@ class QAPISchemaParser(object): > >> return None > >> > >> try: > >> - fobj = open(incl_fname, 'r') > >> + if sys.version_info[0] >= 3: > >> + fobj = open(incl_fname, 'r', encoding='utf-8') > >> + else: > >> + fobj = open(incl_fname, 'r') > > > > I dislike the Python version check, but getting rid of it would > > require rewriting the QAPI modules to not use the Python 2 str > > type (that has different semantics from Python 3 str type). > > The version check is ugly, but it has a property I rather like: when we > drop support for Python 2, the conditional becomes True, and partial > evaluation results in the Python 3 code we actually want. > > > The python-future package would help us write code for a single > > file/string API instead of two different APIs, but it's not a > > QEMU build dependency (yet?), so this patch is good enough for > > now. > > Please do not invest more than absolutely necessary in Python 2 support. > All such investment will turn into technical debt in less than two > years. If you must invest, pick a solution that will result in less > technical debt. We can accept local ugliness for that. > > In my personal opinion, dumb ideas like supporting Python 2 this close > to its EOL ought to look ugly. That's the whole point: python-future allows us to not worry about Python 2 support in the code anymore because it exposes the Python 3 string API (and others) even if we're running Python 2. After we stop supporting Python 2, we can simply delete the "from __future__ import .*" and "from builtins import .*" lines. Anyway, I will send a RFC series demonstrating that, and then we can discuss if it's worth it. My main worry is not the extra imports in Python code, but the introduction of a new build dependency only for a few (one?) releases. > > > Reviewed-by: Eduardo Habkost > > Acked-by: Eduardo Habkost > > Uh, what does "Acked-by" add over "Reviewed-by"? It was supposed to indicate that I agree it can be merged through other maintainers. But it looks like this is not part of the original definition of "Acked-by"? -- Eduardo