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How to set Python's default version to 3.x on OS X?
...tain Lion and the basic default Python version is 2.7. I downloaded Python 3.3 and want to set it as default.
21 Answers
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Why can't R's ifelse statements return vectors?
...tors, you will get longer results:
> ifelse(c(TRUE, FALSE), c(1, 2), c(3, 4))
[1] 1 4
So ifelse is intended for the specific purpose of testing a vector of booleans and returning a vector of the same length, filled with elements taken from the (vector) yes and no arguments.
It is a common con...
Cosine Similarity between 2 Number Lists
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13 Answers
13
Active
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How can I do an asc and desc sort using underscore.js?
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365
You can use .sortBy, it will always return an ascending list:
_.sortBy([2, 3, 1], function(nu...
Single Line Nested For Loops
...f the list comprehension (here (x,y)):
>>> [(x, y) for x in [1,2,3] for y in [3,1,4] if x != y]
[(1, 3), (1, 4), (2, 3), (2, 1), (2, 4), (3, 1), (3, 4)]
It's exactly the same as this nested for loop (and, as the tutorial says, note how the order of for and if are the same).
>>>...
How to avoid reinstalling packages when building Docker image for Python projects?
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143
Try to build a Dockerfile which looks something like this:
FROM my/base
WORKDIR /srv
ADD ./requ...
Integrate ZXing in Android Studio
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234
I was integrating ZXING into an Android application and there were no good sources for the inpu...
Reorder levels of a factor without changing order of values
...f <- data.frame(f = 1:4, g = letters[1:4])
df
# f g
# 1 1 a
# 2 2 b
# 3 3 c
# 4 4 d
levels(df$g)
# [1] "a" "b" "c" "d"
df$g <- factor(df$g, levels = letters[4:1])
# levels(df$g)
# [1] "d" "c" "b" "a"
df
# f g
# 1 1 a
# 2 2 b
# 3 3 c
# 4 4 d
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SQL RANK() versus ROW_NUMBER()
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answered Oct 12 '11 at 22:38
Ritesh MengjiRitesh Mengji
5,03688 gold badges2727 silver badges4646 bronze badges
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What does the “map” method do in Ruby?
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432
The map method takes an enumerable object and a block, and runs the block for each element, out...