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Python: fastest way to create a list of n lists
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The probably only way which is marginally faster than
d = [[] for x in xrange(n)]
is
from itertools import repeat
d = [[] for i in repeat(None, n)]
It does not have to create a new int object in every iteration and is about 15 % faster on my machine.
Edi...
How to do parallel programming in Python?
For C++, we can use OpenMP to do parallel programming; however, OpenMP will not work for Python. What should I do if I want to parallel some parts of my python program?
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How to get the original value of an attribute in Rails
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Before rails 5.1
Appending _was to your attribute will give you the previous value.
For rails 5.1+
Copied from Lucas Andrade's answer below: https://stackoverflow.com/a/50973808/9359123
Appending _was is deprecated in rails 5.1, now you should ap...
How does one create an InputStream from a String? [duplicate]
...may not be the one you want here). For me, this is UTF-8 (which can encode all Java Strings). The right answer would be "indicate the encoding you really want", not "use UTF-16". And you can use it with .getBytes(charsetName), don't have to explicitly create a Charset object and encode the String to...
How to convert a scala.List to a java.util.List?
...1,2,3))
From Scala 2.8 onwards:
import scala.collection.JavaConversions._
import scala.collection.mutable.ListBuffer
asList(ListBuffer(List(1,2,3): _*))
val x: java.util.List[Int] = ListBuffer(List(1,2,3): _*)
However, asList in that example is not necessary if the type expected is a Java List,...
python list in sql query as parameter
... performed the same query. Doing this I got the erroy i.e. Type Error: not all arguments converted during string formatting. How am I supposed to solbe it
– TechJhola
Jan 9 '15 at 19:55
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Escape quotes in JavaScript
I'm outputting values from a database (it isn't really open to public entry, but it is open to entry by a user at the company -- meaning, I'm not worried about XSS ).
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Automatic vertical scroll bar in WPF TextBlock?
...g its vertical height. I expected a vertical scroll bar to appear automatically when that happens, but it didn't. I tried to look for a scroll bar property in the Properties pane, but could not find one.
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C# 4.0 optional out/ref arguments
Does C# 4.0 allow optional out or ref arguments?
9 Answers
9
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Algorithm for creating a school timetable
...ere are known solutions for algorithm of creating a school timetable. Basically, it's about optimizing "hour-dispersion" (both in teachers and classes case) for given class-subject-teacher associations. We can assume that we have sets of classes, lesson subjects and teachers associated with each ot...