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Select distinct values from a table field
...uery, not even the default ordering, call order_by() with no parameters.
and distinct() in the note where it discusses issues with using distinct() with ordering.
To query your DB, you just have to call:
models.Shop.objects.order_by().values('city').distinct()
It returns a dictionnary
or
mod...
How to use RSpec's should_raise with any kind of exception?
...e_method }.should raise_error
See the documentation (for RSpec 1 syntax) and RSpec 2 documentation for more.
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Hide all warnings in ipython
I need to produce a screencast of an ipython session, and to avoid confusing viewers, I want to disable all warnings emitted by warnings.warn calls from different packages. Is there a way to configure the ipythonrc file to automatically disable all such warnings?
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Preview layout with merge root tag in Intellij IDEA/Android Studio
...
There is a new parentTag tools attribute (added in Android Studio 2.2) that you can use to specify the layout type for a merge tag, which will make the layout render correctly in the layout editor preview.
So using your example:
<merge xmlns:android="http://schemas.andr...
Transpose a data frame
I need to transpose a large data frame and so I used:
4 Answers
4
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SQL RANK() versus ROW_NUMBER()
...rows that have duplicate values,in which case the same ranking is assigned and a gap appears in the sequence for each duplicate ranking.
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How to go back to previous page if back button is pressed in WebView?
...bView:
private WebView mWebView;
Initialize it in the onCreate() method and you should be good to go.
mWebView = (WebView) findViewById(R.id.webView);
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Is the C# static constructor thread safe?
.... https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/static-constructors
The implementation shown is thread safe for the initial construction, that is, no locking or null testing is required for constructing the Singleton object. However, this does not mean that an...
Android Closing Activity Programmatically
...ity.finish() method (quoting) :
Call this when your activity is done
and should be closed.
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Default argument values in JavaScript functions [duplicate]
...ined') a = 10;
if (typeof(b)==='undefined') b = 20;
//your code
}
and then you can call it like func(); to use default parameters.
Here's a test:
function func(a, b){
if (typeof(a)==='undefined') a = 10;
if (typeof(b)==='undefined') b = 20;
alert("A: "+a+"\nB: "+b);
}
//testing
...