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How do I correctly clean up a Python object?
__del__(self) above fails with an AttributeError exception. I understand Python doesn't guarantee the existence of "global variables" (member data in this context?) when __del__() is invoked. If that is the case and this is the reason for the exception, how do I make sure the object destructs...
Does C++ support 'finally' blocks? (And what's this 'RAII' I keep hearing about?)
...lock()
{
m_.release();
}
};
// A class which uses 'mutex' and 'lock' objects
class foo
{
mutex mutex_; // mutex for locking 'foo' object
public:
void bar()
{
lock scopeLock(mutex_); // lock object.
foobar(); // an operation which may throw an exception
...
Adding a column to a data.frame
...xt, [[.data.frame.
Data frames can be indexed in several modes. When [ and [[ are used with a single vector index (x[i] or x[[i]]), they index the data frame as if it were a list.
my.dataframe["new.col"] <- a.vector
my.dataframe[["new.col"]] <- a.vector
The data.frame method for $, ...
How to automatically crop and center an image
... any arbitrary image, I want to crop a square from the center of the image and display it within a given square.
7 Answers
...
What is the cleanest way to get the progress of JQuery ajax request?
...ng a request, processing the request in the backend to generate some data, and return it back. How can the client side possibly know what is being done in the backend and how much time it will take that it can calculate the progress?
– SexyBeast
Apr 30 '17 at 2...
Use of Finalize/Dispose method in C#
...have to, but you give inheritors of your class a hook to call your Dispose and implement a finalizer themselves if they use unmanaged resources directly:
public class C : B
{
private IntPtr m_Handle;
protected override void Dispose(bool disposing)
{
if (disposing)
{
...
Google Maps v3 - limit viewable area and zoom level
...a certain area? I want to allow displaying only some area (e.g. a country) and disallow the user to slide elsewhere. Also I want to restrict the zoom level - e.g. only between levels 6 and 9. And I want to use all the base map types.
...
Does use of final keyword in Java improve the performance?
...s, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn't been overridden - until it loads a class which overrides the method, at which point it can undo (or partially undo) those optimizati...
What does “=>” mean in PHP?
...the context of that foreach loop, it assigns the key of the array to $user and the value to $pass.
Example:
$user_list = array(
'dave' => 'apassword',
'steve' => 'secr3t'
);
foreach ($user_list as $user => $pass) {
echo "{$user}'s pass is: {$pass}\n";
}
// Prints:
// "dave's...
Double vs. BigDecimal?
I have to calculate some floating point variables and my colleague suggest me to use BigDecimal instead of double since it will be more precise. But I want to know what it is and how to make most out of BigDecimal ?
...