Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!goblin3!goblin2!goblin.stu.neva.ru!newsfeed.xs4all.nl!newsfeed3a.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 0.027 X-Spam-Evidence: '*H*': 0.95; '*S*': 0.00; 'python.': 0.02; 'builtin': 0.09; 'url:github': 0.09; 'python': 0.11; 'checking,': 0.16; 'hasattr(obj,': 0.16; 'iterated': 0.16; 'iterator': 0.16; 'iterators': 0.16; 'rarely': 0.16; 'input': 0.22; 'bytes': 0.24; 'propose': 0.24; 'asking': 0.27; 'function': 0.29; 'message- id:@mail.gmail.com': 0.30; 'code': 0.31; 'checking': 0.33; 'created': 0.35; 'problem.': 0.35; 'something': 0.35; 'received:google.com': 0.35; 'there': 0.35; 'returning': 0.36; 'two': 0.37; 'to:addr:python-list': 0.38; 'fact': 0.38; 'that,': 0.38; 'use.': 0.39; 'to:addr:python.org': 0.39; 'most': 0.60; 'new': 0.61; 'simple': 0.61; 'here:': 0.62; 'times': 0.62; 'address': 0.63; 'great': 0.65; 'determine': 0.67 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:from:date:message-id:subject:to:content-type; bh=h6EjA180qlhtlwYF0GtGBqvSKf8VGhoXVDk/DIj9f74=; b=JWTfDx6xtLVd7D19LwEvUZiqQL6BwTg5Gdb4xhKQXL737P97X8TxHSYAwpUm9i96eT JAX0Kw45QRb2BRjXBNuh07kbg9eWacBdjn3TQ7Uk6HwssO1CNs6pXdVh0ng31KkkFqCK Hj/ssZu7J6ZBMFjNFKv7z6vMMsWWRqsBfWhXI2vlZJVMtraxa+y+c2NyVrR2meq/uivl tHAnqBUyt/yLgmm7HPuQmiQHe4tea4HolCuMvbEuJgCE5Ykp8ihX/K1OlA4z+T4vnmSi hpbLaVUxMTOTETp74UrOdOZDZy+Xu3dYZIbs9N2WpvYuKksDkQFwpt5bhUVZfjyr/N4d rxgg== X-Received: by 10.112.219.3 with SMTP id pk3mr18356378lbc.18.1416124668223; Sat, 15 Nov 2014 23:57:48 -0800 (PST) MIME-Version: 1.0 From: Garrett Berg Date: Sun, 16 Nov 2014 00:57:27 -0700 Subject: isiter builtin To: python-list@python.org Content-Type: multipart/alternative; boundary=001a11c3d9facea6f30507f5379c 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: 1416124670 news.xs4all.nl 2839 [2001:888:2000:d::a6]:53088 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:80861 --001a11c3d9facea6f30507f5379c Content-Type: text/plain; charset=UTF-8 I have been working with python for a few years now, and two of my favorite features about it are iterators and duck typing. The fact that every iterator under the sun can be accessed with a simple for loop is one of the most amazing features of python. However, there are times when I want to do type checking, and the builtin function *isinstance* is of great use. However, this function fails to be satisfactory in returning whether the object is a valid iterator. The call hasattr(obj, '__iter__') also fails because str and bytes types both have that, and are rarely what you mean when you are asking if something is an iterator (how often have you iterated over a string?) I propose a new builtin to address this problem. I have created code for it here: https://gist.github.com/cloudformdesign/de9b54d30547ddd28ec4 This will allow simple type checking on an input to determine whether it is an iterator. --001a11c3d9facea6f30507f5379c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

I have been working= with python for a few years now, and two of my favorite features about it = are iterators and duck typing. The fact that every iterator under the sun c= an be accessed with a simple for loop is one of the most amazing features o= f python.

However, there are times when I want to do typ= e checking, and the builtin function isinstance=C2=A0is of great use= . However, this function fails to be satisfactory in returning whether the = object is a valid iterator. The call hasattr(obj, '__iter__') also = fails because str and bytes types both have that, and are rarely what you m= ean when you are asking if something is an iterator (how often have you ite= rated over a string?)

I propose a new builtin to address = this problem. I have created code for it here:

https://gist.github.com/cloud= formdesign/de9b54d30547ddd28ec4

<= br>

This will allow simple type checking = on an input to determine whether it is an iterator.

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