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get size of json object
... check the size i.e. like that:
var data = {one : 1, two : 2, three : 3};
_.size(data);
//=> 3
_.keys(data);
//=> ["one", "two", "three"]
_.keys(data).length;
//=> 3
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Pandas every nth row
...simpler solution to the accepted answer that involves directly invoking df.__getitem__.
df = pd.DataFrame('x', index=range(5), columns=list('abc'))
df
a b c
0 x x x
1 x x x
2 x x x
3 x x x
4 x x x
For example, to get every 2 rows, you can do
df[::2]
a b c
0 x x x
...
Which is best way to define constants in android, either static class, interface or xml resource?
... advantages of using project resources is the ease of access and that they allow you to organize your project significantly.
static final constants are compiled into the java bytecode; project resources are compiled into a binary format within the apk. Accessing either is extremely efficient... if ...
How to use dashes in HTML-5 data-* attributes in ASP.NET MVC
...an underscore.
For example:
@Html.TextBoxFor(vm => vm.City, new { data_bind = "foo" })
will render this in MVC 3:
<input data-bind="foo" id="City" name="City" type="text" value="" />
If you're still using an older version of MVC, you can mimic what MVC 3 is doing by creating this sta...
Why have header files and .cpp files? [closed]
...dencies so that code that uses the header doesn't necessarily need to know all the details of the implementation and any other classes/headers needed only for that. This will reduce compilation times and also the amount of recompilation needed when something in the implementation changes.
It's not ...
VB.NET equivalent to C# var keyword [duplicate]
...ype '<variablename>' is not defined." - and VarType(variable) is actually just the VB version of variable.GetType() which returns the type of the instance stored in the variable at runtime) I used:
Function MyVarType(Of T)(ByRef Var As T) As Type
Return GetType(T)
End Function
In detail...
Why should hash functions use a prime number modulus?
...
Usually a simple hash function works by taking the "component parts" of the input (characters in the case of a string), and multiplying them by the powers of some constant, and adding them together in some integer type. So for e...
Remove ALL styling/formatting from hyperlinks
...ting it, you COULD use !important, but you shouldn't. It's a bad habit to fall into.
.nav a { color:green !important; } /*I'm a bad person and shouldn't use !important */
Then it'll always be green, irrelevant of any other rule.
...
Is it a good practice to use try-except-else in Python?
...o, the use of exceptions in Python does not slow the surrounding code and calling code as it does in some compiled languages (i.e. CPython already implements code for exception checking at every step, regardless of whether you actually use exceptions or not).
In other words, your understanding that...
Linux下部署企业级邮件服务器(postfix + dovecot + extmail) - 开源 & Gith...
...环境配置
1、安装一下过程中所依赖的一些rpm包
yum install -y tcl-devel libart_lgpl-devel libtool-ltdl-devel
2、关闭sendmail，并取消其开机启动
service sendmail stop
chkconfig sendmail off
3、配置编译环境，安装开发包组
yum groupinstall -y "Develop...