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Does the join order matter in SQL?
Disregarding performance, will I get the same result from query A and B below? How about C and D?
4 Answers
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Python syntax for “if a or b or c but not all of them”
...ve either zero or three command line arguments. (Either it runs on default behavior or needs all three values specified.)
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How to compare two colors for similarity/difference
I want to design a program that can help me assess between 5 pre-defined colors which one is more similar to a variable color, and with what percentage. The thing is that I don't know how to do that manually step by step. So it is even more difficult to think of a program.
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What is the best way to concatenate two vectors?
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AB.reserve( A.size() + B.size() ); // preallocate memory
AB.insert( AB.end(), A.begin(), A.end() );
AB.insert( AB.end(), B.begin(), B.end() );
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Why doesn't Java offer operator overloading?
Coming from C++ to Java, the obvious unanswered question is why didn't Java include operator overloading?
16 Answers
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Insert an element at a specific index in a list and return the updated list
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l.insert(index, obj) doesn't actually return anything. It just updates the list.
As ATO said, you can do b = a[:index] + [obj] + a[index:].
However, another way is:
a = [1, 2, 4]
b = a[:]
b.insert(2, 3)
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Circular list iterator in Python
I need to iterate over a circular list, possibly many times, each time starting with the last visited item.
6 Answers
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What's a correct and good way to implement __hash__()?
... easy, correct way to implement __hash__() is to use a key tuple. It won't be as fast as a specialized hash, but if you need that then you should probably implement the type in C.
Here's an example of using a key for hash and equality:
class A:
def __key(self):
return (self.attr_a, sel...
String concatenation: concat() vs “+” operator
Assuming String a and b:
11 Answers
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Can we make unsigned byte in Java
I am trying to convert a signed byte in unsigned. The problem is the data I am receiving is unsigned and Java does not support unsigned byte, so when it reads the data it treats it as signed.
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