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Why .NET String is immutable? [duplicate]
...formance win in the case in question). With mutable objects that can't be done.
No side-effects can come from passing an immutable type as a method to a parameter unless it is out or ref (since that changes the reference, not the object). A programmer therefore knows that if string x = "abc" at the ...
Django: “projects” vs “apps”
...tent.
There are no hard and fast rules saying you must do this, but it is one of the goals of the framework. The fact that everything, templates included, allows you to include from some common base means your blog should fit snugly into any other setup, simply by looking after its own part.
Howev...
How does data binding work in AngularJS?
...ntrast dirty-checking (AngularJS) vs change listeners (KnockoutJS and Backbone.js): While dirty-checking may seem simple, and even inefficient (I will address that later), it turns out that it is semantically correct all the time, while change listeners have lots of weird corner cases and need thing...
How to convert a data frame column to numeric type?
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Here goes: first two columns are character. I've deliberately called 2nd one fake_char. Spot the similarity of this character variable with one that Dirk created in his reply. It's actually a numerical vector converted to character. 3rd and 4th column are factor, and the last one is "purely" numer...
Set active tab style with AngularJS
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Just one thing: Better set $scope.activeTab = $route.current.activetab so that you can keep the html a little cleaner.
– Christoph
Apr 15 '13 at 20:12
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How can I get the concatenation of two lists in Python without modifying either one? [duplicate]
...eturns the concatenation of the lists:
concat = first_list + second_list
One disadvantage of this method is that twice the memory is now being used . For very large lists, depending on how you're going to use it once it's created, itertools.chain might be your best bet:
>>> import iterto...
Converting Dictionary to List? [duplicate]
...ust specify it between square brackets as shown above. And we could have done dictlist.append([key,value]) if we wanted to be as brief as possible.
Or just use dict.items() as has been suggested.
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Is MVC a Design Pattern or Architectural pattern
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Why does one of them have to be true?
Both can be true, depending on point of view.
MVC can be an architectual pattern, if it forms the basis of the application architecture.
It can also be seen as simply a design pattern, an abst...
Create a “with” block on several context managers? [duplicate]
...se, but if you have an unknown-length list of context managers you'll need one of the below methods.
In Python 3.3, you can enter an unknown-length list of context managers by using contextlib.ExitStack:
with ExitStack() as stack:
for mgr in ctx_managers:
stack.enter_context(mgr)
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Cosine Similarity between 2 Number Lists
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Just a reminder that Passing one dimension arrays as input data is deprecated in sklearn version 0.17, and will raise ValueError in 0.19.
– Chong Tang
Mar 11 '16 at 14:36
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