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How to reorder data.table columns (without copying)
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Use setcolorder():
library(data.table)
x <- data.table(a = 1:3, b = 3:1, c = runif(3))
x
# a b c
# [1,] 1 3 0.2880365
# [2,] 2 2 0.7785115
# [3,] 3 1 0.3297416
setcolorder(x, c("c", "b", "a"))
x
# c b a
# [1,] 0.2880365 3 1
# [2,] 0.7785115 2 2
# [3,] 0.329741...
Remove rows with duplicate indices (Pandas DataFrame and TimeSeries)
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I would suggest using the duplicated method on the Pandas Index itself:
df3 = df3[~df3.index.duplicated(keep='first')]
While all the other methods work, the currently accepted answer is by far the least performant for the provided example. Furthermore, while the groupby method is only slightly les...
What does {0} mean when initializing an object?
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303
What's happening here is called aggregate initialization. Here is the (abbreviated) definitio...
Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?
... and boolean False are still properly returned for comparisons.
In Python 3.x True and False are keywords and will always be equal to 1 and 0.
Under normal circumstances in Python 2, and always in Python 3:
False object is of type bool which is a subclass of int:
object
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int
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bool
It...
How to host a Node.Js application in shared hosting [closed]
...xtract the latest node
exec('curl http://nodejs.org/dist/latest/node-v0.10.33-linux-x86.tar.gz | tar xz');
//Rename the folder for simplicity
exec('mv node-v0.10.33-linux-x86 node');
2) The same way install your node app, e.g. jt-js-sample, using npm:
<?php
exec('node/bin/npm install jt-js-sam...
PHP append one array to another (not array_push or +)
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436
array_merge is the elegant way:
$a = array('a', 'b');
$b = array('c', 'd');
$merge = array_mer...
Resizing an image in an HTML5 canvas
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396
So what do you do if all the browsers (actually, Chrome 5 gave me quite good one) won't give y...
Undefined method 'task' using Rake 0.9.0
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edited Jul 31 '11 at 13:34
Peter Mortensen
26.5k2121 gold badges9292 silver badges122122 bronze badges
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What to use as an initial version? [closed]
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answered Sep 16 '10 at 16:39
community wiki
Bet...