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correct way to define class variables in Python [duplicate]
...hey are just two different kinds of class elements:
Elements outside the __init__ method are static elements; they belong to the class.
Elements inside the __init__ method are elements of the object (self); they don't belong to the class.
You'll see it more clearly with some code:
class MyClass...
Which $_SERVER variables are safe?
...lue comes from and hence whether it can be trusted for a certain purpose. $_SERVER['HTTP_FOOBAR'] for example is entirely safe to store in a database, but I most certainly wouldn't eval it.
As such, let's divide those values into three categories:
Server controlled
These variables are set by the ...
Objective-C : BOOL vs bool
...
From the definition in objc.h:
#if (TARGET_OS_IPHONE && __LP64__) || TARGET_OS_WATCH
typedef bool BOOL;
#else
typedef signed char BOOL;
// BOOL is explicitly signed so @encode(BOOL) == "c" rather than "C"
// even if -funsigned-char is used.
#endif
#defin...
How to get all registered routes in Express?
...t app.routes :-)
express 4.x
Applications - built with express()
app._router.stack
Routers - built with express.Router()
router.stack
Note: The stack includes the middleware functions too, it should be filtered to get the "routes" only.
...
How can I link to a specific glibc version?
...clude <limits.h>
#include <stdlib.h>
#include <stdio.h>
__asm__(".symver realpath,realpath@GLIBC_2.2.5");
int main()
{
const char* unresolved = "/lib64";
char resolved[PATH_MAX+1];
if(!realpath(unresolved, resolved))
{ return 1; }
printf("%s\n", resolved)...
App Inventor 2 向心力实验App - 探究向心力F与角速度ω、半径r、质量m的关...
...a
初始化局部变量 m = 取文本为数字(文本输入框_质量.文本)
初始化局部变量 r = 取文本为数字(文本输入框_半径.文本)
设置 全局变量 向心力 为 m × 全局变量 向心加速度
设置 标...
Calling C/C++ from Python?
...ed to provide those declaring them as extern "C"
extern "C" {
Foo* Foo_new(){ return new Foo(); }
void Foo_bar(Foo* foo){ foo->bar(); }
}
Next you have to compile this to a shared library
g++ -c -fPIC foo.cpp -o foo.o
g++ -shared -Wl,-soname,libfoo.so -o libfoo.so foo.o
And finally...
实时预览录制使用指导 · App Inventor 2 中文网
...
拖一个实时预览录制、一个垂直布局（改名 垂直布局_预览，宽「充满」、高 400 像素）当预览区，
再放 按钮_录制、按钮_停止、一个视频播放器；
搭下面的代码块：
各案例独立使用；组合到同一屏幕时，将同名事件的...
clang error: unknown argument: '-mno-fused-madd' (python package installation failure)
...s/2.7/include/python2.7 -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -mno-fused-madd -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DT...
Duplicate symbols for architecture x86_64 under Xcode
...
75 duplicate symbols for architecture x86_64
Means that you have loaded same functions twice.
As the issue disappear after removing -ObjC from Other Linker Flags,
this means that this option result that functions loads twice:
from Technical Q&A
This fl...