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Why doesn't Python have a sign function?
...er the desired behavior for edge cases - which sometimes might require the call to cmp(x,0).
I don't know why it's not a built-in, but I have some thoughts.
copysign(x,y):
Return x with the sign of y.
Most importantly, copysign is a superset of sign! Calling copysign with x=1 is the same as a...
Laravel Schema onDelete set null
...re you set the foreign key field as nullable:
$table->integer('foreign_id')->unsigned()->nullable();
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Load data from txt with pandas
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if you want to call a column use data.a if you named the column "a".
– pietrovismara
Feb 4 '14 at 8:01
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BLE（二）信道&数据包&协议栈格式 - 创客硬件开发 - 清泛IT社区，...
...BLUETOOTH SPECIFICATION Version 4.0 [Vol 6] Part B 2.4）
LLID（逻辑链路ID）：0x01表示该数据包是一个帧的延续内容，或者这是一个空的“逻辑链路控制及适配协议”数据包；0x02表示一个“逻辑链路控制及适配协议”数据包的开始...
What is a lambda expression in C++11?
...ll be const when you access them by default. This has the effect that each call with the same input would produce the same result, however you can mark the lambda as mutable to request that the operator() that is produced is not const.
...
Database Structure for Tree Data Structure
...ik Ben-Gann has a good overview of the most common options in his book "Inside Microsoft SQL Server 2005: T-SQL Querying".
The main things to consider when choosing a model are:
1) Frequency of structure change - how frequently does the actual structure of the tree change. Some models provide bett...
Array or List in Java. Which is faster?
...Vector without rewriting all your code.
In fact, the ArrayList was specifically designed to replace the low-level array construct in most contexts. If Java was being designed today, it's entirely possible that arrays would have been left out altogether in favor of the ArrayList construct.
Sinc...
How to change the background color of a UIButton while it's highlighted?
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Why nobody had mentioned that the setter is being called only when you tap the button, but not during the initial layout! So by default there is no colour until you touch the button. So to make it work you also need to explicitly call isHighlighted = false somewhere in the b...
How to write a:hover in inline CSS?
...swer: you can't.
Long answer: you shouldn't.
Give it a class name or an id and use stylesheets to apply the style.
:hover is a pseudo-selector and, for CSS, only has meaning within the style sheet. There isn't any inline-style equivalent (as it isn't defining the selection criteria).
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How to trigger jQuery change event in code
... something like:
$(document).ready(function() {
$("#yourInitialElementID").change(function() {
// Do something here...
$(".yourDropDownClass").change();
});
});
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