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Convert nested Python dict to object?
...a dict with some nested dicts and lists (i.e. javascript-style object syntax).
39 Answers
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val-mutable versus var-immutable in Scala
...trive for referential transparency. What that means is that, if I have an expression "e", I could make a val x = e, and replace e with x. This is the property that mutability break. Whenever you need to make a design decision, maximize for referential transparency.
As a practical matter, a method-l...
What does |= (ior) do in Python?
...R, binary operation
In most cases, it is related to the | operator. See examples below.
Sets
For example, the union of two assigned sets s1 and s2 share the following equivalent expressions:
>>> s1 = s1 | s12 # 1
>>> s1 |= s2 ...
Where and why do I have to put the “template” and “typename” keywords?
...why do I have to put typename and template on dependent names?
What exactly are dependent names anyway?
6 Answers
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How do I use vim registers?
...y know of one instance using registers is via Ctrl R * whereby I paste text from a clipboard.
16 Answers
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How do I call one constructor from another in Java?
...
Yes, it is possible:
public class Foo {
private int x;
public Foo() {
this(1);
}
public Foo(int x) {
this.x = x;
}
}
To chain to a particular superclass constructor instead of one in the same class, use super instead of this. Note that you c...
Nested defaultdict of defaultdict
...ber of levels:
def rec_dd():
return defaultdict(rec_dd)
>>> x = rec_dd()
>>> x['a']['b']['c']['d']
defaultdict(<function rec_dd at 0x7f0dcef81500>, {})
>>> print json.dumps(x)
{"a": {"b": {"c": {"d": {}}}}}
Of course you could also do this with a lambda, but ...
What are good uses for Python3's “Function Annotations”
...no constructs that made this straightforward and part of the official syntax.
There are other uses for annotations beyond assurance. I can see how I could apply my Java-based tools to Python. For instance, I have a tool that lets you assign special warnings to methods, and gives you indications wh...
Drawing an image from a data URL to a canvas
...ge or purely in JS) by setting the src of the image to your data URL. For example:
var img = new Image;
img.src = strDataURI;
The drawImage() method of HTML5 Canvas Context lets you copy all or a portion of an image (or canvas, or video) onto a canvas.
You might use it like so:
var myCanvas = d...
C# 4.0 optional out/ref arguments
...ication, section 21.1:
Formal parameters of constructors, methods, indexers and delegate types can be declared optional:
fixed-parameter:
attributesopt parameter-modifieropt type identifier default-argumentopt
default-argument:
= expression
A fixed-parameter ...