Bugs item #1543347, was opened at 2006-08-20 01:59 Message generated for change (Comment added) made by tim_one You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1543347&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Interpreter Core Group: Python 2.3 Status: Closed Resolution: Works For Me Priority: 5 Submitted By: [N/A] (ymasuda) Assigned to: Nobody/Anonymous (nobody) Summary: Operator precedence inconsistent for complex literal Initial Comment: Using complex, real and imag attributes are computed collectly as follows: >>> 1+2j (1+2j) >>> z = 1+2j >>> z.real 1.0 >>> z.imag 2.0 >>> (1+2j).real 1.0 >>> (1+2j).imag 2.0 But, if there's no explicit literal boundary, it seems to break consistensy in operator precedence: >>> 1+2j.real # addition succeeds j-suffux 1.0 >>> 1+2j.imag # addition precedes (j-suffix and) attribute reference 3.0 >>> 0+1+2j.real # same as above 1.0 >>> 0+1+2j.imag 3.0 >>> 1+0+2j.imag 3.0 >>> 1+0+2j.real 1.0 >>> 1+(2j).imag # brace puts no bless 3.0 >>> 1*1+2j.imag # star fails to steer 3.0 This happens at least on Python 2.3.5 (OSX bundled), Python 2.4.2 (build from ports, FreeBSD 5.4). # Practically, of course, you always explicit (1+2j) to construct complex thus hardly troubled with this :) but it would be happy for beginners to mention it on standard tutorial or something. ---------------------------------------------------------------------- >Comment By: Tim Peters (tim_one) Date: 2006-08-20 12:52 Message: Logged In: YES user_id=31435 Note that Python doesn't have complex literals, only imaginary literals: 1+2j is the integer 1 added to the imaginary literal 2j. IOW, it's the same as (1)+(2j) = 1 + complex(0, 2). Everything follows from that; e.g., 0+1+2j.imag is parsed as (0+1)+(2j.imag) = 1 + 2.0 = 3.0. ---------------------------------------------------------------------- Comment By: Georg Brandl (gbrandl) Date: 2006-08-20 10:37 Message: Logged In: YES user_id=849994 I can't see anything inconsistent here. Attribute access always happens before "+" or "*" are applied. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1543347&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
