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Random record from MongoDB
...
Do a count of all records, generate a random number between 0 and the count, and then do:
db.yourCollection.find().limit(-1).skip(yourRandomNumber).next()
share
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How do I fix PyDev “Undefined variable from import” errors?
...ncing the same issue with latest Eclipse and PyDev. I can navigate between all modules, so why code-analysis can't do the same?
– Adam
Sep 3 '14 at 11:41
3
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JavaScript object: access variable property by name as string [duplicate]
...racket notation.
If you NEED a function for it, here it is:
function read_prop(obj, prop) {
return obj[prop];
}
To answer some of the comments below that aren't directly related to the original question, nested objects can be referenced through multiple brackets. If you have a nested objec...
Linux command to print directory structure in the form of a tree
... /proc
|-- fd
| `-- 3 -> /proc/15589/fd
|-- fdinfo
|-- net
| |-- dev_snmp6
| |-- netfilter
| |-- rpc
| | |-- auth.rpcsec.context
| | |-- auth.rpcsec.init
| | |-- auth.unix.gid
| | |-- auth.unix.ip
| | |-- nfs4.idtoname
| | |-- nfs4.nametoid
| | |-- nfsd.export
...
What Does 'Then' Really Mean in CasperJS
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then() basically adds a new navigation step in a stack. A step is a javascript function which can do two different things:
waiting for the previous step - if any - being executed
waiting for a requested url and related page to load
...
Declaring an enum within a class
...uct Color
{
enum Type
{
Red, Green, Black
};
Type t_;
Color(Type t) : t_(t) {}
operator Type () const {return t_;}
private:
//prevent automatic conversion for any other built-in types such as bool, int, etc
template<typename T>
operator T () const;
};
...
Linux环境离线安装docker&docker-compose - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
Linux环境离线安装docker&docker-composelinux_docker_install一、docker离线安装1、下载docker离线安装包下载最新版本的 docker （或者选择自己想要安装的版本）到本地。1）docker下载地址：Docker版本下载 ||Docker-compose版本下载备注...
一、docker...
Fatal error: “No Target Architecture” in Visual Studio
...
_WIN32 identifier is not defined.
use #include <SDKDDKVer.h>
MSVS generated projects wrap this include by generating a local "targetver.h"which is included by "stdafx.h" that is comiled into a precompiled-header throu...
How to call a parent class function from derived class function?
...disambiguate it by adding the base class's name followed by two colons base_class::foo(...). You should note that unlike Java and C#, C++ does not have a keyword for "the base class" (super or base) since C++ supports multiple inheritance which may lead to ambiguity.
class left {
public:
void f...
Programmatically saving image to Django ImageField
...import File # you need this somewhere
import urllib
# The following actually resides in a method of my model
result = urllib.urlretrieve(image_url) # image_url is a URL to an image
# self.photo is the ImageField
self.photo.save(
os.path.basename(self.url),
File(open(result[0], 'rb'))
...