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Nested defaultdict of defaultdict
...ber of levels:
def rec_dd():
return defaultdict(rec_dd)
>>> m>x m> = rec_dd()
>>> m>x m>['a']['b']['c']['d']
defaultdict(<function rec_dd at 0m>x m>7f0dcef81500>, {})
>>> print json.dumps(m>x m>)
{"a": {"b": {"c": {"d": {}}}}}
Of course you could also do this with a lambda, but ...
What does |= (ior) do in Python?
...R, binary operation
In most cases, it is related to the | operator. See em>x m>amples below.
Sets
For em>x m>ample, the union of two assigned sets s1 and s2 share the following equivalent em>x m>pressions:
>>> s1 = s1 | s12 # 1
>>> s1 |= s2 ...
iPhone UIButton - image position
I have a UIButton with tem>x m>t "Em>x m>plore the app" and UIImage (>)
In Interface Builder it looks like:
15 Answers
...
Where do I find the bashrc file on Mac?
...pse development environment.
However I am not too sure how to go about em>x m>ecuting this step:
7 Answers
...
How to get first element in a list of tuples?
...st(unzipped[0])
[1, 2]
Edit (@BradSolomon):
The above works for Python 2.m>x m>, where zip returns a list.
In Python 3.m>x m>, zip returns an iterator and the following is equivalent to the above:
>>> print(list(list(zip(*inpt))[0]))
[1, 2]
...
C# 4.0 optional out/ref arguments
...ication, section 21.1:
Formal parameters of constructors, methods, indem>x m>ers and delegate types can be declared optional:
fim>x m>ed-parameter:
attributesopt parameter-modifieropt type identifier default-argumentopt
default-argument:
= em>x m>pression
A fim>x m>ed-parameter ...
How do I em>x m>tract a sub-hash from a hash?
...
If you specifically want the method to return the em>x m>tracted elements but h1 to remain the same:
h1 = {:a => :A, :b => :B, :c => :C, :d => :D}
h2 = h1.select {|key, value| [:b, :d, :e, :f].include?(key) } # => {:b=>:B, :d=>:D}
h1 = Hash[h1.to_a - h2.to_a...
How do I call one constructor from another in Java?
...
Yes, it is possible:
public class Foo {
private int m>x m>;
public Foo() {
this(1);
}
public Foo(int m>x m>) {
this.m>x m> = m>x m>;
}
}
To chain to a particular superclass constructor instead of one in the same class, use super instead of this. Note that you c...
What are good uses for Python3's “Function Annotations”
...no constructs that made this straightforward and part of the official syntam>x m>.
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...
Determining memory usage of objects? [duplicate]
...time ago I stole this little nugget from here:
sort( sapply(ls(),function(m>x m>){object.size(get(m>x m>))}))
it has served me well
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