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Dynamically select data frame columns using $ and a character value
... a reproducible example below:
# set seed for reproducibility
set.seed(123)
df <- data.frame( col1 = sample(5,10,repl=T) , col2 = sample(5,10,repl=T) , col3 = sample(5,10,repl=T) )
# We want to sort by 'col3' then by 'col1'
sort_list <- c("col3","col1")
# Use 'do.call' to call order. Sec...
List of lists into numpy array
...answer of Ignacio Vazquez-Abrams will not work. Instead there are at least 3 options:
1) Make an array of arrays:
x=[[1,2],[1,2,3],[1]]
y=numpy.array([numpy.array(xi) for xi in x])
type(y)
>>><type 'numpy.ndarray'>
type(y[0])
>>><type 'numpy.ndarray'>
2) Make an arr...
Is there a 'foreach' function in Python 3?
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user 451
35255 silver badges88 bronze badges
answered Aug 18 '13 at 0:33
Jo Are ByJo Are By
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How to remove last n characters from every element in the R vector
...rame("data"=char_array,"data2"=1:4)
a$data = substr(a$data,1,nchar(a$data)-3)
a should now contain:
data data2
1 foo_ 1
2 bar_ 2
3 ap 3
4 b 4
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Python multiprocessing pool.map for multiple arguments
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388
The answer to this is version- and situation-dependent. The most general answer for recent ver...
What are 'get' and 'set' in Swift?
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38
That's actually explained right before the code:
In addition to simple properties that are sto...
Is there a common Java utility to break a list into batches?
...e, partitioning a list containing [a, b, c, d, e] with a partition size of 3 yields [[a, b, c], [d, e]] -- an outer list containing two inner lists of three and two elements, all in the original order.
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Right to Left support for Twitter Bootstrap 3
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answered Nov 1 '13 at 16:11
Muhammad RedaMuhammad Reda
23.4k1212 gold badges8383 silver badges9999 bronze badges
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Responsive image align center bootstrap 3
I do a catalog using Bootstrap 3. When displayed on tablets, the product images look ugly because of their small size (500x500) and a width of 767 pixels in the browser. I want to put the image in the center of the screen, but for some reason I can not. Who be will help solve the problem?
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How to check if type of a variable is string?
...d to test whether an object is an instance of str or unicode.
In Python 3.x, the correct test is
isinstance(s, str)
The bytes class isn't considered a string type in Python 3.
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