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How to index into a dictionary?
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Dictionaries are unordered in Python versions up to and including Python 3.6. If you do not care about the order of the entries and want to access the keys or values by index anyway, you can use d.keys()[i] and d.values()[i] or d.items()[i]. (Note that these methods create a list of all keys, va...
Accessing last x characters of a string in Bash
I found out that with ${string:0:3} one can access the first 3 characters of a string. Is there a equivalently easy method to access the last three characters?
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List of installed gems?
... >> Platform 0.4.0
# >> abstract 1.0.0
# >> actionmailer 3.0.5
# >> actionpack 3.0.5
# >> activemodel 3.0.5
# >> activerecord 3.0.5
Here's an updated way to get a list:
require 'rubygems'
def local_gems
Gem::Specification.sort_by{ |g| [g.name.downcase, g....
Using jQuery to compare two arrays of Javascript objects
...s are in different order.
NOTE: This works only for jquery versions < 3.0.0 when using JSON objects
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Programmatically creating Markdown tables in R with KnitR
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Now knitr (since version 1.3) package include the kable function for a creation tables:
> library(knitr)
> kable(head(iris[,1:3]), format = "markdown")
| Sepal.Length| Sepal.Width| Petal.Length|
|-------------:|------------:|-------------:|
|...
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...
Python 3 ImportError: No module named 'ConfigParser'
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373
In Python 3, ConfigParser has been renamed to configparser for PEP 8 compliance. It looks like...
Python matplotlib multiple bars
...ime.datetime(2011, 1, 6, 0, 0)
]
x = date2num(x)
y = [4, 9, 2]
z = [1, 2, 3]
k = [11, 12, 13]
ax = plt.subplot(111)
ax.bar(x-0.2, y, width=0.2, color='b', align='center')
ax.bar(x, z, width=0.2, color='g', align='center')
ax.bar(x+0.2, k, width=0.2, color='r', align='center')
ax.xaxis_date()
plt....
efficient circular buffer?
...in xrange(20):
... d.append(i)
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>>> d
deque([10, 11, 12, 13, 14, 15, 16, 17, 18, 19], maxlen=10)
There is a recipe in the docs for deque that is similar to what you want. My assertion that it's the most efficient rests entirely on the fact that it's implemented in C by an incredib...