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In-place type conversion of a NumPy array
...different dtype, and then copy in-place into the view:
import numpy as np
x = np.arange(10, dtype='int32')
y = x.view('float32')
y[:] = x
print(y)
yields
array([ 0., 1., 2., 3., 4., 5., 6., 7., 8., 9.], dtype=float32)
To show the conversion was in-place, note that copying from x to y...
When should I really use noexcept?
The noexcept keyword can be appropriately applied to many function signatures, but I am unsure as to when I should consider using it in practice. Based on what I have read so far, the last-minute addition of noexcept seems to address some important issues that arise when move constructors throw....
What is the __del__ method, How to call it?
...ave been deleted.
In a simple case this could be right after you say del x or, if x is a local variable, after the function ends. In particular, unless there are circular references, CPython (the standard Python implementation) will garbage collect immediately.
However, this is an implementation...
传感器组件 · App Inventor 2 中文网
...2)在三个维度上近似测量加速度。其组成部分是：
X分量：当手机静止在平坦表面上时为 0，当手机倾斜时为正向右（即左侧抬起），当手机倾斜到右侧时为负向左（即，其右侧尺寸升高）。
Y分量：当手机静止在平...
Number of occurrences of a character in a string [duplicate]
...:
int count = test.Split('&').Length - 1;
Or with LINQ:
test.Count(x => x == '&');
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How do I check if an element is really visible with JavaScript? [duplicate]
...point 2.
I see that no one has suggested to use document.elementFromPoint(x,y), to me it is the fastest way to test if an element is nested or hidden by another. You can pass the offsets of the targetted element to the function.
Here's PPK test page on elementFromPoint.
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pandas: filter rows of DataFrame with operator chaining
...etc), but the only way I've found to filter rows is via normal bracket indexing
14 Answers
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Why can I access private variables in the copy constructor?
...
IMHO, existing answers do a poor job explaining the "Why" of this - focusing too much on reiterating what behaviour's valid. "access modifiers work on class level, and not on object level." - yes, but why?
The overarching concept ...
What is tail call optimization?
...s optimization (JavaScript does also, starting with ES6), so here are two examples of the factorial function in Scheme:
(define (fact x)
(if (= x 0) 1
(* x (fact (- x 1)))))
(define (fact x)
(define (fact-tail x accum)
(if (= x 0) accum
(fact-tail (- x 1) (* x accum))))
(fa...
Installing libv8 gem on OS X 10.9+
I'm trying to install libv8 3.16.14.3 but getting an error on OSX Mavericks using latest stable rvm and ruby-1.9.3-p125.
20...