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List comprehension on a nested list?
...w you would do this with a nested list comprehension:
[[float(y) for y in x] for x in l]
This would give you a list of lists, similar to what you started with except with floats instead of strings. If you want one flat list then you would use [float(y) for x in l for y in x].
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How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
I have two Python dictionaries, and I want to write a single expression that returns these two dictionaries, merged (i.e. taking the union). The update() method would be what I need, if it returned its result instead of modifying a dictionary in-place.
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How to evaluate a math expression given in string form?
I'm trying to write a Java routine to evaluate math expressions from String values like:
25 Answers
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++someVariable vs. someVariable++ in JavaScript
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Same as in other languages:
++x (pre-increment) means "increment the variable; the value of the expression is the final value"
x++ (post-increment) means "remember the original value, then increment the variable; the value of the expression is the origina...
How to create a new object instance from a Type
...http://msdn.microsoft.com/en-us/library/system.activator.createinstance.aspx
or (new path)
https://docs.microsoft.com/en-us/dotnet/api/system.activator.createinstance
Here are some simple examples:
ObjectType instance = (ObjectType)Activator.CreateInstance(objectType);
ObjectType instance ...
What's the difference between a continuation and a callback?
...ghtenment about continuations, and it's mind boggling how the simplest of explanations can so utterly confound a JavaScript programmer like myself. This is especially true when most articles explain continuations with code in Scheme or use monads.
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How to smooth a curve in the right way?
Lets assume we have a dataset which might be given approximately by
9 Answers
9
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Remove all the elements that occur in one list from another
...List Comprehensions that is perfectly suited to making this sort of thing extremely easy. The following statement does exactly what you want and stores the result in l3:
l3 = [x for x in l1 if x not in l2]
l3 will contain [1, 6].
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Number.sign() in javascript
...er / Math.abs(number); in case number = 0
– NullUserException
Oct 2 '11 at 6:27
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List comprehension vs. lambda + filter
...le (value). That is slower than accessing a local variable and in Python 2.x the list comprehension only accesses local variables. If you are using Python 3.x the list comprehension runs in a separate function so it will also be accessing value through a closure and this difference won't apply.
The...