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Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript?
...king at CoffeeScript if you want an alternative syntax. It has some shorthand that is similar to what you are looking for.
For example The Existential Operator
zip = lottery.drawWinner?().address?.zipcode
Function shortcuts
()-> // equivalent to function(){}
Sexy function calling
func '...
When saving, how can you check if a field has changed?
... if you make changes to the object, save it, then makes additional changes and call save() on it AGAIN, it will still work correctly.
– philfreo
Mar 14 '12 at 22:57
17
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How to shift a column in Pandas DataFrame
I would like to shift a column in a Pandas DataFrame , but I haven't been able to find a method to do it from the documentation without rewriting the whole DF. Does anyone know how to do it?
DataFrame:
...
How to do parallel programming in Python?
...ment: ` dict.items()` work. The error raises, because I had to change the handling of the variable insight the process-funktion. Unfortunately the error-message was not very helpful... So: thank you for your hint. :-)
– The Bndr
Jun 10 '15 at 15:41
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Capturing URL parameters in request.GET
...haha, you would use request.GET.get('q', '').
q is the parameter you want, and '' is the default value if q isn't found.
However, if you are instead just configuring your URLconf**, then your captures from the regex are passed to the function as arguments (or named arguments).
Such as:
(r'^user/(?P&...
Convert a matrix to a 1 dimensional array
...
That's a vector, and not a 1-d array.
– hadley
Sep 29 '10 at 20:35
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How to rotate portrait/landscape Android emulator? [duplicate]
I am new to Android development.
I know if you change a android phone from portrait to landscape sometimes the app relays its self out on the screen.. so how do I simulate rotating a phone with the emulator?
On the Blackberry emulators there's a button in the menu to turn the phone, but I can't f...
Can I set enum start value in Java?
... just labels for integers.
Java enums are implemented more like classes - and they can even have multiple attributes.
public enum Ids {
OPEN(100), CLOSE(200);
private final int id;
Ids(int id) { this.id = id; }
public int getValue() { return id; }
}
The big difference is that th...
Get last record in a queryset
...no real
effect (the ordering was undefined
prior to calling reverse(), and will
remain undefined afterward).
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Error to run Android Studio
I have installed Android Studio and I followed all steps described here
17 Answers
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