built-in

tl;dr: How come property decorators work with class-level function definitions, but not with module-level definitions? I was applying property decorators to some module-level functions, thinking they would allow me to invoke the methods by mere attribute lookup. This was particularly tempting because I was defining a set of configuration functions, like get_port , get_hostname , etc., all of which could have been replaced with their simpler, more terse property counterparts: port , hostname , etc. Thus, config.get_port() would just be the much nicer config.port I was surprised when I found the

I accidentally overwrote set by using it as a variable name in an interactive python session - is there any way that I can get access to the original set function without just restarting my session? (I have so much stuff in that session that I'd rather not have to do that, although of course I can if necessary.) Martijn Pieters Just delete the name that is masking the builtin: >>> set = 'oops' >>> set 'oops' >>> del set >>> set <type 'set'> You can always still access the original built-in through the __builtins__ namespace; use this if you want to override the built-in but want to defer to

I try to extend JavaScript Math . But one thing surprised me. When I tried to extend it by prototype Math.prototype.randomBetween = function (a, b) { return Math.floor(Math.random() * (b - a + 1) + a); }; In console I have error 'Cannot set property 'randomBetween' of undefined' ... But if I asigne this function to Math.__proto__ Math.__proto__.randomBetween = function (a, b) { return Math.floor(Math.random() * (b - a + 1) + a); }; Then everything works fine. Can anybody explain me why it works in this way? I appreciate any help. Math isn't a constructor, so it doesn't have prototype property:

I would like to overload only one type of subsref calls (the '()' type) for a particular class and leave any other calls to Matlab's built in subsref -- specifically, I want Matlab to handle property/method access via the '.' type. But, it seems like Matlab's 'builtin' function doesn't work when subsref is overloaded in a class. Consider this class: classdef TestBuiltIn properties testprop = 'This is the built in method'; end methods function v = subsref(this, s) disp('This is the overloaded method'); end end end To use the overloaded subsref method, I do this: t = TestBuiltIn; t.testprop >>

For code: #!/usr/bin/python src = """ print '!!!' import os """ obj = compile(src, '', 'exec') eval(obj, {'__builtins__': False}) I get output: !!! Traceback (most recent call last): File "./test.py", line 9, in <module> eval(obj, {'__builtins__': False}) File "", line 3, in <module> ImportError: __import__ not found Both 'print' and 'import' are language construct. Why does 'eval' restrict using of 'import' but doesn't restrict 'print'? P.S. I'm using python 2.6 UPDATE: Question is not "Why does import not work?" but "Why does print work?" Are there some architecture restrictions or something

What is the equivalent to __builtin_popcount as found in GCC and Clang, for MSVC-10? Using the comments provided: __popcnt available through <intrin.h> _mm_popcnt_u64 with SSE4 and <nmmintrin.h> Eric Nicolas With this code snippet you get the GCC builtin when building with MSVC : #ifdef _MSC_VER # include <intrin.h> # define __builtin_popcount __popcnt #endif (Works from Visual Studio 2008). The __popcount intrinsic mentioned above doesn't work on ARM, or even all x86 CPUs (it requires ABM instruction set). You shouldn't use it directly; instead, if you're on x86/amd64 you should use the _