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How to iterate a loop with index and element in Swift
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print("Item \(index): \(element)")
}
Before Swift 3.0 and after Swift 2.0, the function was called enumerate():
for (index, element) in list.enumerate() {
print("Item \(index): \(element)")
}
Prior to Swift 2.0, enumerate was a global function.
for (index, element) in enumerate(list) {
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HSL to RGB color conversion
...m, but is archived here and the original author has a gist - thanks to user2441511).
The code is re-posted below:
HSL to RGB:
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes h, s, and l are contained in the se...
How to find the sum of an array of numbers
Given an array [1, 2, 3, 4] , how can I find the sum of its elements? (In this case, the sum would be 10 .)
43 Answers
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Get column index from column name in python pandas
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Sure, you can use .get_loc():
In [45]: df = DataFrame({"pear": [1,2,3], "apple": [2,3,4], "orange": [3,4,5]})
In [46]: df.columns
Out[46]: Index([apple, orange, pear], dtype=object)
In [47]: df.columns.get_loc("pear")
Out[47]: 2
although to be honest I don't often need this myself. Usu...
How to add an extra column to a NumPy array
...np.random.rand(N,N)
b = np.zeros((N,N+1))
b[:,:-1] = a
And timings:
In [23]: N = 10
In [24]: a = np.random.rand(N,N)
In [25]: %timeit b = np.hstack((a,np.zeros((a.shape[0],1))))
10000 loops, best of 3: 19.6 us per loop
In [27]: %timeit b = np.zeros((a.shape[0],a.shape[1]+1)); b[:,:-1] = a
1000...
How do I use floating-point division in bash?
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248
You can't. bash only does integers; you must delegate to a tool such as bc.
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How to find the size of localStorage
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226
Execute this snippet in JavaScript console (one line version):
var _lsTotal=0,_xLen,_x;for(_x ...
How do I create a list of random numbers without duplicates?
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edited Apr 2 '18 at 12:59
nbro
10.9k1717 gold badges7676 silver badges140140 bronze badges
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Backporting Python 3 open(encoding=“utf-8”) to Python 2
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1. To get an encoding parameter in Python 2:
If you only need to support Python 2.6 and 2.7 you can use io.open instead of open. io is the new io subsystem for Python 3, and it exists in Python 2,6 ans 2.7 as well. Please be aware that in Python 2.6 (as well as 3.0) ...
Using Python String Formatting with Lists
I construct a string s in Python 2.6.5 which will have a varying number of %s tokens, which match the number of entries in list x . I need to write out a formatted string. The following doesn't work, but indicates what I'm trying to do. In this example, there are three %s tokens and the list ...