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How to take the first N items from a generator or list in Python? [duplicate]
...Slicing a list
top5 = array[:5]
To slice a list, there's a simple syntax: array[start:stop:step]
You can omit any parameter. These are all valid: array[start:], array[:stop], array[::step]
Slicing a generator
import itertools
top5 = itertools.islice(my_list, 5) # grab the first five element...
How can I handle R CMD check “no visible binding for global variable” notes when my ggplot2 syntax i
...instead of aes? This should work, although I haven't tried it:
aes_string(x = 'x.values', y = 'y.values')
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Bitwise operation and usage
...wise it's 0.
OR is 1 if one or both of its inputs are 1, otherwise it's 0.
XOR is 1 only if exactly one of its inputs are 1, otherwise it's 0.
NOT is 1 only if its input is 0, otherwise it's 0.
These can often be best shown as truth tables. Input possibilities are on the top and left, the resulta...
Drawing Isometric game worlds
... technique for mapping the tiles to the screen can be said that the tile's x and y coordinates are on the vertical and horizontal axes.
"Drawing in a diamond" approach:
By drawing an isometric map using "drawing in a diamond", which I believe refers to just rendering the map by using a nested for-...
Convert nullable bool? to bool
...will represent. If null should be false, you can do this:
bool newBool = x.HasValue ? x.Value : false;
Or:
bool newBool = x.HasValue && x.Value;
Or:
bool newBool = x ?? false;
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Does it make sense to use “as” instead of a cast even if there is no null check? [closed]
In development blogs, online code examples and (recently) even a book, I keep stumbling about code like this:
13 Answers
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How do I draw a grid onto a plot in Python?
...ot using pylab in Python and now I would like to superimpose a grid of 10x10 onto the scatter plot. How do I do that?
5 A...
How to install a specific JDK on Mac OS X?
I want to install a specific JDK (the latest for example). For this, I went to the JDK download homepage: http://java.sun.com/javase/downloads/index.jsp .
I looked for a Mac version, but I'm a bit surprised to only see downloadable versions for Linux, Windows and Solaris ...
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Why doesn't c++ have &&= or ||= for booleans?
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The reason is that b & 2 performs integer promotion such that the expression is then equivalent to static_cast<int>(b) & 2, which results in 0, which is then converted back into a bool. So it’s true that the existence of an operator &&= would improve type safety.
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Structure padding and packing
... char gap_1[3]; /* -"-: for alignment of the whole struct in an array */
} x;
Packing, on the other hand prevents compiler from doing padding - this has to be explicitly requested - under GCC it's __attribute__((__packed__)), so the following:
struct __attribute__((__packed__)) mystruct_A {
c...