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What are all the uses of an underscore in Scala?
...],T](a: K[T])
Ignored variables
val _ = 5
Ignored parameters
List(1, 2, 3) foreach { _ => println("Hi") }
Ignored names of self types
trait MySeq { _: Seq[_] => }
Wildcard patterns
Some(5) match { case Some(_) => println("Yes") }
Wildcard patterns in interpolations
"abc" matc...
Get: TypeError: 'dict_values' object does not support indexing when using python 3.2.3 [duplicate]
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answered Jul 2 '13 at 17:10
andersschullerandersschuller
11.5k22 gold badges3535 silver badges3333 bronze badges
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Flatten nested dictionaries, compressing keys
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28 Answers
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How can I access and process nested objects, arrays or JSON?
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26 Answers
26
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How to get the difference between two arrays in JavaScript?
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What are the differences between numpy arrays and matrices? Which one should I use?
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answered Apr 11 at 11:52
AksAks
27633 silver badges66 bronze badges
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How to map with index in Ruby?
...methods like map on. So you can do:
arr.each_with_index.map { |x,i| [x, i+2] }
In 1.8.6 you can do:
require 'enumerator'
arr.enum_for(:each_with_index).map { |x,i| [x, i+2] }
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How to fix/convert space indentation in Sublime Text?
Example: If I have a document with 2 space indentation, and I want it to have 4 space indentation, how do I automatically convert it by using the Sublime Text editor?
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pandas GroupBy columns with NaN (missing) values
...e groupby (e.g. -1):
In [11]: df.fillna(-1)
Out[11]:
a b
0 1 4
1 2 -1
2 3 6
In [12]: df.fillna(-1).groupby('b').sum()
Out[12]:
a
b
-1 2
4 1
6 3
That said, this feels pretty awful hack... perhaps there should be an option to include NaN in groupby (see this github issue ...
Real life example, when to use OUTER / CROSS APPLY in SQL
...me,
pa.name
FROM sys.procedures pr
OUTER APPLY (SELECT TOP 2 *
FROM sys.parameters pa
WHERE pa.object_id = pr.object_id
ORDER BY pr.name) pa
ORDER BY pr.name,
pa.name
2) Calling a Table Valued Function for ...