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How to get the difference between two arrays in JavaScript?
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Simultaneously merge multiple data.frames in a list
...question was marked as a duplicate of this one so I answer here, using the 3 sample data frames below:
x <- data.frame(i = c("a","b","c"), j = 1:3, stringsAsFactors=FALSE)
y <- data.frame(i = c("b","c","d"), k = 4:6, stringsAsFactors=FALSE)
z <- data.frame(i = c("c","d","a"), l = 7:9, stri...
Get column index from column name in python pandas
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388
Sure, you can use .get_loc():
In [45]: df = DataFrame({"pear": [1,2,3], "apple": [2,3,4], "or...
How to profile a bash shell script slow startup?
My bash shell takes up to 3-4 seconds to start up, while if I start it with --norc it runs immediately.
7 Answers
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How to get all possible combinations of a list’s elements?
...a list with 15 numbers in, and I need to write some code that produces all 32,768 combinations of those numbers.
27 Answer...
Converting int to bytes in Python 3
I was trying to build this bytes object in Python 3:
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Logic to test that 3 of 4 are True
I want to return True if and only if 3 out of 4 boolean values are true.
27 Answers
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Rotating a two-dimensional array in Python
...ider the following two-dimensional list:
original = [[1, 2],
[3, 4]]
Lets break it down step by step:
>>> original[::-1] # elements of original are reversed
[[3, 4], [1, 2]]
This list is passed into zip() using argument unpacking, so the zip call ends up being the equiva...
Formatting Phone Numbers in PHP
...MS app and need to be able to convert the sender's phone number from +11234567890 to 123-456-7890 so it can be compared to records in a MySQL database .
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Numpy - add row to array
... If it is a 2D-array, how can you then compare its row to a number: i < 3?
EDIT after OP's comment:
A = array([[0, 1, 2], [0, 2, 0]])
X = array([[0, 1, 2], [1, 2, 0], [2, 1, 2], [3, 2, 0]])
add to A all rows from X where the first element < 3:
import numpy as np
A = np.vstack((A, X[X[:,0]...