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Fastest way to get the first object from a queryset in django?
...eturn None if there aren't any. There are lots of ways to do this which all work. But I'm wondering which is the most performant.
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What does the “@” symbol mean in reference to lists in Haskell?
...hout the @, you'd have to choose between (1) or (2):(3).
This syntax actually works for any constructor; if you have data Tree a = Tree a [Tree a], then t@(Tree _ kids) gives you access to both the tree and its children.
s...
How can I generate random alphanumeric strings?
...retty much linearly when generating longer strings (so long as there's actually enough memory available). Having said that, Dan Rigby's answer was almost twice as fast as this one in every test.
– LukeH
Aug 28 '09 at 0:33
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Complete Working Sample of the Gmail Three-Fragment Animation Scenario?
...at I'll refer to as "the Gmail three-fragment animation" scenario. Specifically, we want to start with two fragments, like this:
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How to set specific java version to Maven
On my machine I have two java versions installed: (1.6 and 1.7 installed manually by me). I need both of them for different projects. But for Maven I need 1.7, now my Maven uses 1,6 java version, how can I set Maven to use 1.7?
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Get bitcoin historical data [closed]
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Maxim Mikhaylov
56377 silver badges2323 bronze badges
answered Jul 5 '13 at 15:22
SeanSean
41155 silver badges44 b...
Passing Data between View Controllers
...h it onto nav stack.
ViewControllerB *viewControllerB = [[ViewControllerB alloc] initWithNib:@"ViewControllerB" bundle:nil];
viewControllerB.isSomethingEnabled = YES;
[self pushViewController:viewControllerB animated:YES];
This will set isSomethingEnabled in ViewControllerB to BOOL value YES.
P...
Elegant ways to support equivalence (“equality”) in Python classes
When writing custom classes it is often important to allow equivalence by means of the == and != operators. In Python, this is made possible by implementing the __eq__ and __ne__ special methods, respectively. The easiest way I've found to do this is the following method:
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Bash if statement with multiple conditions throws an error
...ions.
tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_01.html
Update
Actually you could still use && and || with the -eq operation. So your script would be like this:
my_error_flag=1
my_error_flag_o=1
if [ $my_error_flag -eq 1 ] || [ $my_error_flag_o -eq 2 ] || ([ $my_error_flag -eq 1 ] ...
What does each of the [y,n,q,a,d,/,K,j,J,g,e,?] stand for in context of git -p
...this hunk nor any of the remaining ones
a - stage this hunk and all later hunks in the file
d - do not stage this hunk nor any of the later hunks in the file
g - select a hunk to go to
/ - search for a hunk matching the given regex
j - leave thi...