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How to pull a random record using Django's ORM?
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count = self.aggregate(count=Count('id'))['count']
random_index = randint(0, count - 1)
return self.all()[random_index]
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Convert light frequency to RGB?
..._MAX)
return new byte[3];
len -= LEN_MIN;
var index = (int)Math.Floor(len / LEN_STEP);
var offset = len - LEN_STEP * index;
var x = Interpolate(X, index, offset);
var y = Interpolate(Y, index, offset);
var z = Interpolate(Z, index, offset...
count(*) vs count(column-name) - which is more correct? [duplicate]
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What about count( col ) where col is a primary indexed column ? I thaught indexes help making tasks faster ?
– Stphane
Aug 28 '15 at 13:47
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Storing R.drawable IDs in XML array
...tResources().obtainTypedArray(R.array.random_imgs);
// get resource ID by index
imgs.getResourceId(i, -1)
// or set you ImageView's resource to the id
mImgView1.setImageResource(imgs.getResourceId(i, -1));
// recycle the array
imgs.recycle();
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Picking a random element from a set
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Fast solution for Java using an ArrayList and a HashMap: [element -> index].
Motivation: I needed a set of items with RandomAccess properties, especially to pick a random item from the set (see pollRandom method). Random navigation in a binary tree is not accurate: trees are not perfectly bal...
Getting started with F# [closed]
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Official entry point is here: Microsoft F# Developer Center
For a quick taste, consider trying F# in your browser (Silverlight). (contains interactive tutorial walkthroughs)
Start by watching videos and presentations (BTW, An Introduction to Microsoft F# by Luca Bolognese is still one of t...
Keep ignored files out of git status
...or untracked files. If you added files to repository, you can:
git update-index --assume-unchanged <file>
or remove them from repository by
git rm --cached <file>
Edit
This article explains that too
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UICollectionView current visible cell index
...tionViewCell *cell in [self.mainImageCollection visibleCells]) {
NSIndexPath *indexPath = [self.mainImageCollection indexPathForCell:cell];
NSLog(@"%@",indexPath);
}
}
Update to Swift 5:
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
for cell in yourCollec...
Exception handling in R [closed]
... since been discontinued, but you can try
Github search as e.g. in this query for tryCatch in language=R;
Ohloh/Blackduck Code search eg this query for tryCatch in R files
the Debian code search engine on top of the whole Debian archive
Just for the record, there is also try but tryCatch may b...
How to hide reference counts in VS2013?
...ght clicking the indicators themselves in the editor:
documented in the Q&A section of the msdn CodeLens documentation
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