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Postgresql aggregate array
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163
Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as marks ...
How to remove all rows in a numpy.ndarray that contain non-numeric values
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>>> a = np.array([[1,2,3], [4,5,np.nan], [7,8,9]])
array([[ 1., 2., 3.],
[ 4., 5., nan],
[ 7., 8., 9.]])
>>> a[~np.isnan(a).any(axis=1)]
array([[ 1., 2., 3.],
[ 7., 8., 9.]])
and reassign this to a...
What is “lifting” in Scala?
...gt;
scala> res1(-1)
res2: Option[Boolean] = None
scala> res1(1)
res3: Option[Boolean] = Some(false)
Methods
You can "lift" a method invocation into a function. This is called eta-expansion (thanks to Ben James for this). So for example:
scala> def times2(i: Int) = i * 2
times2: (i: In...
When does System.getProperty(“java.io.tmpdir”) return “c:\temp”
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130
In MS Windows the temporary directory is set by the environment variable TEMP. In XP, the temp...
What do the python file extensions, .pyc .pyd .pyo stand for?
...ater easier (and faster).
.pyo: This was a file format used before Python 3.5 for *.pyc files that were created with optimizations (-O) flag. (see the note below)
.pyd: This is basically a windows dll file. http://docs.python.org/faq/windows.html#is-a-pyd-file-the-same-as-a-dll
Also for some furt...
Convert list of dictionaries to a pandas DataFrame
...24
cs95
231k6060 gold badges390390 silver badges455455 bronze badges
answered Dec 17 '13 at 15:35
jorisjoris
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Creating my own Iterators
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Chinasaur
1,96222 gold badges1313 silver badges1717 bronze badges
answered Sep 29 '08 at 15:34
RoelRoel
17.8...
rotating axis labels in R
...f axis labels. (0=parallel, 1=all horizontal, 2=all perpendicular to axis, 3=all vertical)
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How do I explicitly specify a Model's table-name mapping in Rails?
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437
Rails >= 3.2 (including Rails 4+ and 5+):
class Countries < ActiveRecord::Base
self.ta...