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Python: fastest way to create a list of n lists
...None, n)]
It does not have to create a new int object in every iteration and is about 15 % faster on my machine.
Edit: Using NumPy, you can avoid the Python loop using
d = numpy.empty((n, 0)).tolist()
but this is actually 2.5 times slower than the list comprehension.
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Is an array name a pointer?
...ame a pointer in C?
If not, what is the difference between an array's name and a pointer variable?
10 Answers
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Iterate a list as pair (current, next) in Python
...ometimes need to iterate a list in Python looking at the "current" element and the "next" element. I have, till now, done so with code like:
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Why is this program erroneously rejected by three C++ compilers?
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In the standard, §2.1/1 specifies:
Physical source file characters are mapped, in an implementation-defined manner, to the basic source character set (introducing new-line characters for end-of-line indicators) if necessary.
Yo...
How do you get the logical xor of two variables in Python?
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Although this is clever and short, I'm not convinced it's clean. When someone reads this construct in the code, is it immediately obvious to them that this is an xor operation? I felt obliged to add a comment - a sign for me that I'm writing unclear...
Generating random integer from a range
I need a function which would generate a random integer in given range (including border values). I don't unreasonable quality/randomness requirements, I have four requirements:
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Regular expression to check if password is “8 characters including 1 uppercase letter, 1 special cha
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The regular expression you are after will most likely be huge and a nightmare to maintain especially for people who are not that familiar with regular expressions.
I think it would be easier to break your regex down and do it one bit at a time. It might take a bit more to do, but I am ...
How to overload functions in javascript?
...ariable arguments - You can pass different sets of arguments (in both type and quantity) and the function will behave in a way that matches the arguments passed to it.
Default arguments - You can define a default value for an argument if it is not passed.
Named arguments - Argument order becomes irr...
What is the difference between Left, Right, Outer and Inner Joins?
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Simple Example: Lets say you have a Students table, and a Lockers table. In SQL, the first table you specify in a join, Students, is the LEFT table, and the second one, Lockers, is the RIGHT table.
Each student can be assigned to a locker, so there is a LockerNumber column in...
Forced naming of parameters in Python
... Parameters after “*” or “*identifier” are keyword-only parameters and
may only be passed used keyword arguments.
>>> def foo(pos, *, forcenamed):
... print(pos, forcenamed)
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>>> foo(pos=10, forcenamed=20)
10 20
>>> foo(10, forcenamed=20)
10 20
>>&g...