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Rails 3: Get Random Record
...NDOM()") # For MySQL :order => "RAND()", - thanx, @DanSingerman
# Rails 3
Thing.order("RANDOM()").first
or
Thing.first(:offset => rand(Thing.count))
# Rails 3
Thing.offset(rand(Thing.count)).first
Actually, in Rails 3 all examples will work. But using order RANDOM is quite slow for big ta...
Why does substring slicing with index out of range work?
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3 Answers
3
Active
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Transpose/Unzip Function (inverse of zip)?
... use the special * operator.
>>> zip(*[('a', 1), ('b', 2), ('c', 3), ('d', 4)])
[('a', 'b', 'c', 'd'), (1, 2, 3, 4)]
The way this works is by calling zip with the arguments:
zip(('a', 1), ('b', 2), ('c', 3), ('d', 4))
… except the arguments are passed to zip directly (after being co...
jQuery - checkbox enable/disable
...checkboxes like this. If the "Check Me" checkbox is checked, all the other 3 checkboxes should be enabled, else they should be disabled. How can I do this using jQuery?
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With CSS, use “…” for overflowed block of multi-lines
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answered Jun 3 '11 at 5:22
Jim ThomasJim Thomas
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phonegap open link in browser
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answered Jul 26 '13 at 17:28
freejoshfreejosh
10.6k33 gold badges2828 silver badges4646 bronze badges
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How does Django's Meta class work?
...:55
Moon
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answered Apr 27 '12 at 3:04
TadeckTadeck
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Weighted random numbers
...andom number that is 0 or greater and is less than the sum of the weights
3) go through the items one at a time, subtracting their weight from your random number, until you get the item where the random number is less than that item's weight
Pseudo-code illustrating this:
int sum_of_weight = 0;
f...
Pandas: drop a level from a multi-level column index?
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321
You can use MultiIndex.droplevel:
>>> cols = pd.MultiIndex.from_tuples([("a", "b"), ...