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C char array initialization
... how you initialize an array, but for:
The first declaration:
char buf[10] = "";
is equivalent to
char buf[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
The second declaration:
char buf[10] = " ";
is equivalent to
char buf[10] = {' ', 0, 0, 0, 0, 0, 0, 0, 0, 0};
The third declaration:
char buf[...
How does Dijkstra's Algorithm and A-Star compare?
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answered Aug 26 '09 at 5:18
leizleiz
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How to select rows from a DataFrame based on column values?
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10 Answers
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Why does ++[[]][+[]]+[+[]] return the string “10”?
This is valid and returns the string "10" in JavaScript ( more examples here ):
9 Answers
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xkcd style graphs in MATLAB
...nshot, and IMTRANSFORM to get a transformation.
%# define plot data
x = 1:0.1:10;
y1 = sin(x).*exp(-x/3) + 3;
y2 = 3*exp(-(x-7).^2/2) + 1;
%# plot
fh = figure('color','w');
hold on
plot(x,y1,'b','lineWidth',3);
plot(x,y2,'w','lineWidth',7);
plot(x,y2,'r','lineWidth',3);
xlim([0.95 10])
ylim([0 5]...
Modifying a subset of rows in a pandas dataframe
...fy this DataFrame (or create a copy) so that B is always NaN whenever A is 0. How would I achieve that?
5 Answers
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Most efficient way to create a zero filled JavaScript array?
...duces Array.prototype.fill. It can be used like this:
new Array(len).fill(0);
Not sure if it's fast, but I like it because it's short and self-describing.
It's still not in IE (check compatibility), but there's a polyfill available.
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Why does the expression 0 < 0 == 0 return False in Python?
... make range comparisons easy to express. It's much nicer to be able to say 0 &lt; x &lt;= 5 than to say (0 &lt; x) and (x &lt;= 5).
These are called chained comparisons. And that's a link to the documentation for them.
With the other cases you talk about, the parenthesis force one relational opera...
What is the most pythonic way to check if an object is a number?
...cimal import Decimal
... from fractions import Fraction
... for n in [2, 2.0, Decimal('2.0'), complex(2, 0), Fraction(2, 1), '2']:
... print(f'{n!r:&gt;14} {isinstance(n, Number)}')
2 True
2.0 True
Decimal('2.0') True
(2+0j) True
Fraction(2, 1) True
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Find MongoDB records where array field is not empty
... the key, you can use:
ME.find({ pictures: { $exists: true, $not: {$size: 0} } })
MongoDB don't use indexes if $size is involved, so here is a better solution:
ME.find({ pictures: { $exists: true, $ne: [] } })
Since MongoDB 2.6 release, you can compare with the operator $gt but could lead to u...