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What is the difference between '>' and a space in CSS selectors?
...o scenarios div > span { } vs. div span { }
Here, the (space) selects all the all the <span> elements inside <div> element even if they are nested inside more than one element. The > selects all the children of <div> element but if they are not inside another element.
Take...
Django-DB-Migrations: cannot ALTER TABLE because it has pending trigger events
...son for this maybe because you try to set a column to NOT NULL when it actually already has NULL values.
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mkdir's “-p” option
...p created both, hello and goodbye
This means that the command will create all the directories necessaries to fulfill your request, not returning any error in case that directory exists.
About rlidwka, Google has a very good memory for acronyms :). My search returned this for example: http://www.cs...
Is there a way to make R beep/play a sound at the end of a script?
...ion sounds in R which should work cross-platform. Run the following to install beepr and make a sound:
install.packages("beepr")
library(beepr)
beep()
More info at github: https://github.com/rasmusab/beepr
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public friend swap member function
...truct vector
{
void swap(vector&) { /* swap members */ }
};
Naturally, then, our class should too, right? Well, not really. The standard library has all sorts of unnecessary things, and a member swap is one of them. Why? Let's go on.
What we should do is identify what's canonical, and w...
Enable SQL Server Broker taking too long
... long as there are transactions pending. Rollback immediate will terminate all of these.
– libjup
Apr 27 '14 at 13:33
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Stop Visual Studio from mixing line endings in files
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I don't have this menu item on my VS2010 ultimate install.
– Palantir
Oct 22 '10 at 8:16
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Xcode variables
...mmand for the shell you're using) and build your project. This will output all of the environment variables that are available to you. You can use this in conjunction with the documentation to make sure you're getting the data that you expected.
– Ryan H.
Mar 9...
How to reorder data.table columns (without copying)
... 2 2
# [3,] 0.3297416 1 3
From ?setcolorder:
In data.table parlance, all set* functions change their input by reference. That is, no copy is made at all, other than temporary working memory, which is as large as one column.
so should be pretty efficient. See ?setcolorder for details.
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Reference: Comparing PHP's print and echo
...hat while they appear to users as two distinct constructs, they are both really shades of echo if you get down to basics, i.e. look at the internal source code. That source code involves the parser as well as opcode handlers. Consider a simple action such as displaying the number zero. Whether you ...