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Difference between Covariance & Contra-variance
...s T → IE<T>. Notice that this is a "thin arrow".
With me so far?
Now let's consider a relation. There is an assignment compatibility relationship between pairs of types in the first set. A value of type Tiger can be assigned to a variable of type Animal, so these types are said to be "assi...
How does collections.defaultdict work?
...
How do we know what is the default value for each type? 0 for int() and [] for list() are intuitive, but there can also be more complex or self-defined types.
– Sean
Mar 11 at 10:40
...
Create RegExps on the fly using string variables
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Note also that when you use a RegExp in replace(), the replacement string now has a special character too, $. This must also be escaped if you want to have a literal $ in your replacement text!
function escapeSubstitute(s) {
return s.replace(/\$/g, '$$$$');
}
(Four $s because that is itself ...
What is the Python equivalent of Matlab's tic and toc functions?
...TicToc, marks the beginning of a time interval
toc(False)
That's it! Now we are ready to fully use tic() and toc() just as in Matlab. For example
tic()
time.sleep(5)
toc() # returns "Elapsed time: 5.00 seconds."
Actually, this is more versatile than the built-in Matlab functions. Here, ...
Fastest way to get the first object from a queryset in django?
...'m pretty sure you'll even see this add LIMIT 1 to the query, and I don't know that you can do any better than this. However, internally __nonzero__ in QuerySet is implemented as try: iter(self).next() except StopIteration: return false... so it doesn't escape the exception.
–...
Fragment or Support Fragment?
...isadvantage so far with this approach.
So my answer to my own question is now: When developing for Android 4.x, using the fragments from the support library is a good idea. The support library has bugs fixed that are still present in older fragment implementations and is frequently updated with mor...
Have the same README both in Markdown and reStructuredText
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2019 Update
The PyPI Warehouse now supports rendering Markdown as well! You just need to update your package configuration and add the long_description_content_type='text/markdown' to it. e.g.:
setup(
name='an_example_package',
# other arguments o...
What is the copy-and-swap idiom?
...rray); // (3)
}
return *this;
}
And we say we're finished; this now manages an array, without leaks. However, it suffers from three problems, marked sequentially in the code as (n).
The first is the self-assignment test. This check serves two purposes: it's an easy way to prevent us fr...
Generate C# class from XML
... tried it and my hair turned white just like the Indiana Jones movie.
But now I use http://xmltocsharp.azurewebsites.net/ and now I'm as young as ever.
Here's a segment of what it generated:
namespace Xml2CSharp
{
[XmlRoot(ElementName="entry")]
public class Entry {
[XmlElement(Ele...
Markdown open a new window link [duplicate]
...m trying to edit a website which uses a modx cms, and it's using Markdown. Now I would like to open a new link into another window.
...