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How to use background thread in swift?
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Swift 3.0+
A lot has been modernized in Swift 3.0. Running something on the background thread looks like this:
DispatchQueue.global(qos: .background).async {
print("This is run on the background queue")
DispatchQueue.mai...
How to iterate a loop with index and element in Swift
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Yes. As of Swift 3.0, if you need the index for each element along with its value, you can use the enumerated() method to iterate over the array. It returns a sequence of pairs composed of the index and the value for each item in the array. F...
Clojure: cons (seq) vs. conj (list)
...ments to insert into a collection, while cons takes just one:
(conj '(1 2 3) 4 5 6)
; => (6 5 4 1 2 3)
(cons 4 5 6 '(1 2 3))
; => IllegalArgumentException due to wrong arity
Another difference is in the class of the return value:
(class (conj '(1 2 3) 4))
; => clojure.lang.PersistentLi...
Removing duplicates from a list of lists
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>>> k = [[1, 2], [4], [5, 6, 2], [1, 2], [3], [4]]
>>> import itertools
>>> k.sort()
>>> list(k for k,_ in itertools.groupby(k))
[[1, 2], [3], [4], [5, 6, 2]]
itertools often offers the fastest and most powerful solutions to this kind of ...
Move an array element from one array position to another
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31 Answers
31
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How can I remove 3 characters at the end of a string in php?
How can I remove 3 characters at the end of a string in php? "abcabcabc" would become "abcabc"!
3 Answers
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In Ruby, is there an Array method that combines 'select' and 'map'?
... as a postfix if. compact gets rid of the nils.
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}
=> [3, 3, 3, nil, nil, nil]
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}.compact
=> [3, 3, 3]
share...
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
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6173
How can I merge two Python dictionaries in a single expression?
For dictionaries x and y, z be...
Is it possible to install another version of Python to Virtualenv?
...rce/v/virtualenv/virtualenv-1.5.2.tar.gz#md5=fbcefbd8520bb64bc24a560c6019a73c
tar -zxvf virtualenv-1.5.2.tar.gz
cd virtualenv-1.5.2/
~/.localpython/bin/python setup.py install
3) Create a virtualenv using your local python
virtualenv docs
mkdir /home/${USER}/virtualenvs
cd /home/${USER}/virtualen...
Deleting an element from an array in PHP
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38 Answers
38
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