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Extract elements of list at odd positions
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Solution
Yes, you can:
l = L[1::2]
And this is all. The result will contain the elements placed on the following positions (0-based, so first element is at position 0, second at 1 etc.):
1, 3, 5
so the result (actual numbers) will be:
2, 4, 6
Explanation...
Optimizing away a “while(1);” in C++0x
...oops?, although this is WG14 document the rationale applies to C++ as well and the document refers to both WG14 and WG21:
As N1509 correctly points out, the current draft essentially gives
undefined behavior to infinite loops in 6.8.5p6. A major issue for
doing so is that it allows code to m...
Why does += behave unexpectedly on lists?
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The general answer is that += tries to call the __iadd__ special method, and if that isn't available it tries to use __add__ instead. So the issue is with the difference between these special methods.
The __iadd__ special method is for an in-place addition, that is it mutates the object that it a...
Does JavaScript guarantee object property order?
... iteration order is a combination of the insertion order for strings keys, and ascending order for number-like keys:
// key order: 1, foo, bar
const obj = { "foo": "foo", "1": "1", "bar": "bar" }
Using an array or a Map object can be a better way to achieve this. Map shares some similarities with O...
How do you determine the size of a file in C?
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You could probably change the return type to ssize_t and cast the size from an off_t without any trouble. It would seem to make more sense to use a ssize_t :-) (Not to be confused with size_t which is unsigned and cannot be used to indicate error.)
– Ted P...
How to get item's position in a list?
I am iterating over a list and I want to print out the index of the item if it meets a certain condition. How would I do this?
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Get all unique values in a JavaScript array (remove duplicates)
...ed to make sure are unique. I found the code snippet below on the internet and it works great until the array has a zero in it. I found this other script here on Stack Overflow that looks almost exactly like it, but it doesn't fail.
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How to clear the canvas for redrawing
After experimenting with composite operations and drawing images on the canvas I'm now trying to remove images and compositing. How do I do this?
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Fast way of finding lines in one file that are not in another?
...ile1 file2
The input files should be sorted for this to work. With bash (and zsh) you can sort in-place with process substitution <( ):
diff --new-line-format="" --unchanged-line-format="" <(sort file1) <(sort file2)
In the above new and unchanged lines are suppressed, so only changed...
What is the difference between “px”, “dip”, “dp” and “sp”?
What is the difference between Android units of measure?
33 Answers
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