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What is the difference between __init__ and __call__?
I want to know the difference between __init__ and __call__ methods.
13 Answers
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Chaining multiple filter() in Django, is this a bug?
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The way I understand it is that they are subtly different by design (and I am certainly open for correction): filter(A, B) will first filter according to A and then subfilter according to B, while filter(A).filter(B) will return a row that ma...
Please explain the exec() function and its family
What is the exec() function and its family? Why is this function used and how does its work?
7 Answers
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Haskell function composition (.) and function application ($) idioms: correct use
I have been reading Real World Haskell , and I am nearing the end, but a matter of style has been niggling at me to do with the (.) and ($) operators.
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How to create a HashMap with two keys (Key-Pair, Value)?
...= 31 * result + y;
return result;
}
}
Implementing equals() and hashCode() is crucial here. Then you simply use:
Map<Key, V> map = //...
and:
map.get(new Key(2, 5));
Table from Guava
Table<Integer, Integer, V> table = HashBasedTable.create();
//...
table.get(2, 5);...
Simpler way to create dictionary of separate variables?
...er the name. I will could use both your anwser. Or maybe just use my damn hand to type. Some things are just not made to be that automatized...
– e-satis
Mar 31 '10 at 14:08
7
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Python function attributes - uses and abuses [closed]
Not many are aware of this feature, but Python's functions (and methods) can have attributes . Behold:
8 Answers
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Visual Studio retrieving an incorrect path to a project from somewhere
Visual Studio (and possibly TFS) has somehow (I think perhaps during a source control merge) become confused about the path of a project within my solution.
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MySQL: Fastest way to count number of rows
...mysql side?
If the COUNT(*) is slow, you should run EXPLAIN on the query, and check if indexes are really used, and where should they be added.
The following is not the fastest way, but there is a case, where COUNT(*) doesn't really fit - when you start grouping results, you can run into problem...
I lost my .keystore file?
... able to retrieve the source code, but not the .keystore file used to sign and publish my application to the market (with several updates). Am I, and my poor users, out of luck if I ever want to update?
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