Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Skip Montanaro Newsgroups: comp.lang.python Subject: Re: I'm missing something here... Date: Mon, 11 Jan 2016 19:04:03 -0600 Lines: 52 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Trace: news.uni-berlin.de 8TWfEFNlc6IXEkpw7AwBHQKBaFAY1P3kcHCiwD7JFMGA== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.005 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'operator': 0.03; 'method.': 0.05; 'subject:missing': 0.07; 'cc:addr:python-list': 0.09; 'output': 0.13; 'argument': 0.15; 'bug,': 0.16; 'call)': 0.16; 'cc:name:python': 0.16; 'lhs': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'rhs': 0.16; 'something.': 0.16; 'skip': 0.18; 'tells': 0.18; 'versions': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; '(the': 0.22; 'sorry,': 0.22; 'ignored.': 0.23; 'thanks,': 0.24; 'tried': 0.24; 'header:In- Reply-To:1': 0.24; 'not.': 0.27; 'least': 0.27; 'message- id:@mail.gmail.com': 0.27; 'actual': 0.28; 'occurred': 0.29; "can't": 0.32; '8bit%:25': 0.33; "i'll": 0.33; 'received:google.com': 0.35; 'set.': 0.35; 'something': 0.35; 'but': 0.36; 'should': 0.36; 'received:209.85': 0.36; 'subject:: ': 0.37; 'two': 0.37; 'list.': 0.37; 'version': 0.38; 'received:209': 0.38; 'does': 0.39; 'bring': 0.62; 'reply': 0.68; '8bit%:21': 0.70; 'skip:\xe2 10': 0.70; '\xc2\xa068': 0.84; 'concluded': 0.91; 'writing,': 0.91; 'convinced': 0.93 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=S5v/he1aE+iQFZ8sVzl1vQJrdVHJ1+9rayrLtqULq3M=; b=ODP4atEX4JqMUeWQCAs/ICLPavF6I+fo8ntccIdiYJktncfWRPxIK2xOQoKCmv2zQA SNkPZfjgkD5Zy6GPxS9KX44ECXI9sy/Hu6JNgNtNBur0Kkm7CeLGWcM0DSZIHNilyiXY W+kVWkSkJ5wMzEVF3FbYxtLJbqFAbc5xmmcWnhZr87UBQOxwQEesVq6cmY8mqJKKYOsG /neWsHJhqU7LeFlCqWYHThFyyfU+QXFuA22F+zzjI4J+s6LiiDgltkXfAkXXhk1RhN9r QNIOfyTZje/9FNJuFCOp5j8rxOuBRvwFqq/QcWgYmzQ6qlU51OuI/eTWIRNy2usJss5l OMYg== X-Received: by 10.140.158.4 with SMTP id e4mr176109999qhe.81.1452560643216; Mon, 11 Jan 2016 17:04:03 -0800 (PST) In-Reply-To: X-Content-Filtered-By: Mailman/MimeDel 2.1.20+ X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com comp.lang.python:101507 Sorry, I should have been explicit. prob_dates (the actual argument of the call) is a set. As far as I know pylint does no type inference, so pylint can't tell if the LHS and RHS of the |=3D operator are appropriate, nor can it tell if it has an update() method. Before writing, I had more-or-less concluded I had hit a bug, but in my experience when I hit something I think is a bug, it's not. It's me. Terry's reply convinced me that I had hit something. Something else just occurred to me. I should have tried disassembling the two versions of the function. Here's the output near prob_dates.update() call: 14 =E2=80=8B =E2=80=8B 62 LOAD_FAST 3 (prob_dates) 65 LOAD_ATTR 6 (update) 68 LOAD_GLOBAL 7 (compare_prices) 71 LOAD_CONST 3 ('E:%s') 74 LOAD_FAST 5 (sym) 77 BINARY_MODULO 78 LOAD_FAST 0 (cx1) 81 LOAD_FAST 1 (cx2) 84 LOAD_FAST 2 (cx3) 87 CALL_FUNCTION 4 90 CALL_FUNCTION 1 Here's how the |=3D version disassembles in that region: 20 =E2=80=8B =E2=80=8B 62 LOAD_FAST 3 (prob_dates) 65 LOAD_GLOBAL 6 (compare_prices) 68 LOAD_CONST 3 ('E:%s') 71 LOAD_FAST 5 (sym) 74 BINARY_MODULO 75 LOAD_FAST 0 (cx1) 78 LOAD_FAST 1 (cx2) 81 LOAD_FAST 2 (cx3) 84 CALL_FUNCTION 4 87 INPLACE_OR 88 STORE_FAST 3 (prob_dates) I think what's throwing pylint is that last =E2=80=8BSTORE_FAST. That tells pylint the argument is ignored. I'll at least bring up the issue on the code-quality list. Thanks, Skip =E2=80=8B