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How can I convert a dictionary into a list of tuples?
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>>> d = { 'a': 1, 'b': 2, 'c': 3 }
>>> d.items()
[('a', 1), ('c', 3), ('b', 2)]
>>> [(v, k) for k, v in d.iteritems()]
[(1, 'a'), (3, 'c'), (2, 'b')]
It's not in the order you want, but dicts don't have any specific order anyway...
How to not run an example using roxygen2?
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answered Aug 20 '12 at 13:03
GSeeGSee
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Is there a difference between x++ and ++x in java?
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293
++x is called preincrement while x++ is called postincrement.
int x = 5, y = 5;
System.out....
How to check whether a pandas DataFrame is empty?
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Dave Thomas
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answered Nov 7 '13 at 5:55
aIKidaIKid
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Select count(*) from multiple tables
...an I select count(*) from two different tables (call them tab1 and tab2 ) having as result:
18 Answers
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Python class inherits object
...nherit from object?
In Python 3, apart from compatibility between Python 2 and 3, no reason. In Python 2, many reasons.
Python 2.x story:
In Python 2.x (from 2.2 onwards) there's two styles of classes depending on the presence or absence of object as a base-class:
"classic" style classes: t...
Ruby, remove last N characters from a string?
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Ruby 2.5+
As of Ruby 2.5 you can use delete_suffix or delete_suffix! to achieve this in a fast and readable manner.
The docs on the methods are here.
If you know what the suffix is, this is idiomatic (and I'd argue, even more r...
Adding rounded corner and drop shadow to UICollectionViewCell
So I already went through various posts on adding 2nd view for adding shadow, but I still cannot get it to work if I want to add it in UICollectionViewCell . I subclassed UICollectionViewCell , and here is my code where I add various UI elements to the cell's content view and adding shadow to the ...
What is the difference between HashSet and List?
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215
Unlike a List<> ...
A HashSet is a List with no duplicate members.
Because a HashSet i...
Order data frame rows according to vector with specific order
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236
Try match:
df <- data.frame(name=letters[1:4], value=c(rep(TRUE, 2), rep(FALSE, 2)))
targe...