Path: csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed1a.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'else:': 0.03; 'value,': 0.04; 'subject:Python': 0.06; "'',": 0.07; 'element': 0.07; 'ignored': 0.07; 'json': 0.07; 'nested': 0.07; 'subject:Question': 0.07; 'transform': 0.07; 'string': 0.09; '===': 0.09; 'pgp': 0.09; 'preferable': 0.09; 'try:': 0.09; 'valueerror:': 0.09; 'variant': 0.09; 'martin': 0.11; '-----begin': 0.16; '-----end': 0.16; 'c_int': 0.16; 'coerced': 0.16; 'gnupg': 0.16; 'hash:': 0.16; 'nesting': 0.16; 'personally,': 0.16; 'practice?': 0.16; 'sha1': 0.16; 'skip:j 60': 0.16; 'language': 0.16; 'thanks,': 0.17; 'wrote:': 0.18; 'message-----': 0.19; 'example': 0.22; 'to:name :python-list@python.org': 0.22; 'integer': 0.24; 'necessary.': 0.24; 'fine': 0.24; 'options': 0.25; 'pass': 0.26; 'signed': 0.27; 'values': 0.27; 'code': 0.31; 'skip:i 60': 0.31; 'this.': 0.32; 'another': 0.32; 'maybe': 0.34; 'except': 0.35; 'something': 0.35; 'options:': 0.36; 'skip:s 60': 0.36; 'version:': 0.36; 'charset :us-ascii': 0.36; 'should': 0.36; 'list': 0.37; 'e.g.': 0.38; 'to:addr:python-list': 0.38; 'does': 0.39; 'to:addr:python.org': 0.39; 'first': 0.61; 'more': 0.64; 'incoming': 0.72; 'received:as9105.com': 0.84; 'received:dsl.as9105.com': 0.84; 'skip:9 60': 0.91; 'received:172.17': 0.93 X-Env-Sender: martin.kemp@ingg.com X-Msg-Ref: server-13.tower-27.messagelabs.com!1414582004!13185322!1 X-Originating-IP: [80.45.145.137] X-StarScan-Received: X-StarScan-Version: 6.12.3; banners=ingg.com,-,- X-VirusChecked: Checked From: Martin Kemp To: "python-list@python.org" Subject: Re: Python Style Question Thread-Topic: Python Style Question Thread-Index: AQHP82WWO+xTm/fqrEiFy9J0pDCw0A== Date: Wed, 29 Oct 2014 11:25:57 +0000 References: <406463d0-1287-49a2-b1ed-08a928db4b94@googlegroups.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.23.126.199] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginalArrivalTime: 29 Oct 2014 11:26:40.0855 (UTC) FILETIME=[35E90E70:01CFF36B] X-Mailman-Approved-At: Wed, 29 Oct 2014 12:43:02 +0100 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 57 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1414582983 news.xs4all.nl 2860 [2001:888:2000:d::a6]:50427 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:79907 -----BEGIN PGP SIGNED MESSAGE-----=0A= Hash: SHA1=0A= =0A= On 29/10/2014 10:45, Anton wrote:=0A= > Let's say I have an incoming list of values *l*. Every element of=0A= > *l* can be one of the following options: 1) an integer value 2) a=0A= > string in form of '', e.g. '7' 3) a string with a json=0A= > serialization of an integer value, e.g. '"7"' 4) something else=0A= > that should be ignored=0A= > =0A= > I need to transform this list into another list with values from=0A= > options 1)-3) coerced to int. The code below should do this.=0A= > =0A= > =0A= > Variant 1 =3D=3D=3D=0A= > =0A= > values =3D [] for c in l: # Case 1) or 2) try: c_int =3D int(c) except=0A= > ValueError: pass else: values.add(c_int) continue=0A= > =0A= > # Case 3) try: c_int =3D int(json.loads(c)) except ValueError: pass =0A= > else: values.add(c_int) continue=0A= > =0A= > =3D=3D=3D=0A= > =0A= > Is this code ugly? Does it follow EAFP? Am I missing something in=0A= > language best practice?=0A= > =0A= > Or maybe below is more preferable way with a nested try...except=0A= > clause?=0A= > =0A= > Variant 2 =3D=3D=3D values =3D [] for c in l: # Case 1) or 2) try: c_int = =3D=0A= > int(c) except ValueError: # Case 3) try: c_int =3D=0A= > int(json.loads(c)) except ValueError: pass else: values.add(c_int) =0A= > continue else: values.add(c_int) continue =3D=3D=3D=0A= > =0A= > Thanks, Anton.=0A= > =0A= > =0A= =0A= Your first example is perfectly fine and is EAFP=0A= =0A= Personally, I prefer to avoid nesting when it's not necessary.=0A= =0A= - -- =0A= Martin Kemp (martin.kemp@ingg.com)=0A= -----BEGIN PGP SIGNATURE-----=0A= Version: GnuPG v2=0A= =0A= iQEcBAEBAgAGBQJUUM7zAAoJEJ0Re0UIDzSucugIALn/zY8RdpP8iaMShHoszzqf=0A= I0zl0mFHyqhNtwgQ0ZF7VGO+H+U0Dk8rhzTYOmEMzPTKNBGwll3fda9mOnrK9Xvp=0A= 9gQjII6DyQIWH7Z3dLcLr2e1j8OMNUSL6UmAYs8urNSIKZLowdV3JI4G/bLyW0KS=0A= y5Ko8dI6y5nOJ1P9XCmPTmags43UZfR8DrBUaAbzNcS8FGwmUE2KBkEhLQOvmpJi=0A= jmMc7wMOpq0jL+XbA+7pHUqoVZ7w1tUFjuy9I3h45tgPuTFAFB0gX+FpE+oVgO5o=0A= spQpVaOPEYN9ceLgHdKSxzdVIhOQLE6H/SYNHlsEW/ZNM6aR9n4yipgkOmtJ0+M=3D=0A= =3DWzHA=0A= -----END PGP SIGNATURE-----=0A=