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What is the difference between Ruby 1.8 and Ruby 1.9
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Array.to_s Now Contains Punctuation
Ruby 1.9
irb(main):001:0> [1,2,3].to_s
=> "[1, 2, 3]"
Ruby 1.8.6
irb(main):001:0> [1,2,3].to_s
=> "123"
Action: Use .join instead
Colon No Longer Valid In When Statements
Ruby 1.9
irb(main):001:0> case 'a'; when /\w/: puts 'word'; end...
pandas GroupBy columns with NaN (missing) values
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138
This is mentioned in the Missing Data section of the docs:
NA groups in GroupBy are automatica...
Uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)
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137
This is an incompatibility between Rails 2.3.8 and recent versions of RubyGems. Upgrade to the ...
Reverse Range in Swift
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Update For latest Swift 3 (still works in Swift 4)
You can use the reversed() method on a range
for i in (1...5).reversed() { print(i) } // 5 4 3 2 1
Or stride(from:through:by:) method
for i in stride(from:5,through:1,by:-1) { print(i) } // 5 4...
What is the significance of initializing direction arrays below with given values when developing ch
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3 Answers
3
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Numpy: Get random set of rows from 2D array
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>>> A = np.random.randint(5, size=(10,3))
>>> A
array([[1, 3, 0],
[3, 2, 0],
[0, 2, 1],
[1, 1, 4],
[3, 2, 2],
[0, 1, 0],
[1, 3, 1],
[0, 4, 1],
[2, 4, 2],
[3, 3, 1]])
>>> idx = np.ran...
How to get row from R data.frame
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130
x[r,]
where r is the row you're interested in. Try this, for example:
#Add your data
x <...
How to perform element-wise multiplication of two lists?
...gahooagahooa
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Move an array element from one array position to another
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31 Answers
31
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How do you remove duplicates from a list whilst preserving order?
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31 Answers
31
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