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Count number of objects in list [closed]
R function that will return the number of items in a list?
5 Answers
5
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When should you not use virtual destructors?
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There is no need to use a virtual destructor when any of the below is true:
No intention to derive classes from it
No instantiation on the heap
No intention to store in a pointer of a superclass
No specific reason to avoid it unless you are really so pressed for memory.
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How to keep a git branch in sync with master
At the moment git is doing my head in, I cannot come up with the best solution for the following.
6 Answers
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Which iomanip manipulators are 'sticky'?
I recently had a problem creating a stringstream due to the fact that I incorrectly assumed std::setw() would affect the stringstream for every insertion, until I changed it explicitly. However, it is always unset after the insertion.
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How to catch integer(0)?
...of printing a zero length vector (an integer one), so you could test for a being of length 0:
R> length(a)
[1] 0
It might be worth rethinking the strategy you are using to identify which elements you want, but without further specific details it is difficult to suggest an alternative strategy....
is it possible to `git status` only modified files?
Is it possible to git status and show only modified files?
16 Answers
16
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Load data from txt with pandas
...pd.read_csv('output_list.txt', sep=" ", header=None)
data.columns = ["a", "b", "c", "etc."]
Add sep=" " in your code, leaving a blank space between the quotes. So pandas can detect spaces between values and sort in columns. Data columns is for naming your columns.
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Can someone explain Microsoft Unity?
I've been reading the articles on MSDN about Unity (Dependency Injection, Inversion of Control), but I think I need it explained in simple terms (or simple examples). I'm familiar with the MVPC pattern (we use it here), but I just can't really grasp this Unity thing yet, and I think it's the next st...
Assignment inside lambda expression in Python
I have a list of objects and I want to remove all objects that are empty except for one, using filter and a lambda expression.
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What does the [Flags] Enum Attribute mean in C#?
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The [Flags] attribute should be used whenever the enumerable represents a collection of possible values, rather than a single value. Such collections are often used with bitwise operators, for example:
var allowedColors = MyColor.Red | MyCol...