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What does `:_*` (colon underscore star) do in Scala?
...tes: MetaData, scope: NamespaceBinding,
child: Node*)
which is called as
new Elem(prefix, label, attributes, scope,
child1, child2, ... childN)
but here there is only a sequence, not child1, child2, etc. so this allows the result sequence to be used as the input to the constru...
Polymorphism in C++
...ecific code selected?
Run time means the compiler must generate code for all the types the program might handle while running, and at run-time the correct code is selected (virtual dispatch)
Compile time means the choice of type-specific code is made during compilation. A consequence of this: say...
Django set default form values
...ch is explained here
You have two options either populate the value when calling form constructor:
form = JournalForm(initial={'tank': 123})
or set the value in the form definition:
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
...
How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
See changes to a specific file using git
...s, but, as far as I understood, it is directory based. This means it gives all the changes of all files on the current directory.
...
Differences between lodash and underscore [closed]
...h run in Node, Ringo, Rhino, Narwhal, PhantomJS, and browsers), better overall performance and optimizations for large arrays/object iteration, and more flexibility with custom builds and template pre-compilation utilities.
Because Lo-Dash is updated more frequently than Underscore, a lodash unders...
How does BLAS get such extreme performance?
...e optimization. This boost significantly exceeds the second boost from parallelism and other hardware optimizations.
By the way, most (or even all) of the high performance BLAS implementations are NOT implemented in Fortran. ATLAS is implemented in C. GotoBLAS/OpenBLAS is implemented in C and i...
Zooming MKMapView to fit annotation pins?
...ew.h:
// Position the map such that the provided array of annotations are all visible to the fullest extent possible.
- (void)showAnnotations:(NSArray *)annotations animated:(BOOL)animated NS_AVAILABLE(10_9, 7_0);
share
...
How to make good reproducible pandas examples
...s.
Disclaimer: Writing a good question is HARD.
The Good:
do include small* example DataFrame, either as runnable code:
In [1]: df = pd.DataFrame([[1, 2], [1, 3], [4, 6]], columns=['A', 'B'])
or make it "copy and pasteable" using pd.read_clipboard(sep='\s\s+'), you can format the text for Sta...
How do I partially update an object in MongoDB so the new object will overlay / merge with the exist
...n would be that you are happy with $set, but do not want to explicitly set all fields. How would you pass in the data then?
You know you can do the following:
db.collection.update( { _id:...} , { $set: someObjectWithNewData }
...