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Which method performs better: .Any() vs .Count() > 0?

...le<T> sequence. For just IEnumerable<T>, then Any() will generally be quicker, as it only has to look at one iteration. However, note that the LINQ-to-Objects implementation of Count() does check for ICollection<T> (using .Count as an optimisation) - so if your underlying data-sou...
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How to pass a user defined argument in scrapy spider

... The above code is only partially working for me. For eg. If I define domain using self.domain, I'm still not able to access it outside the __init__ method. Python throws a not defined error. BTW, why have you omitted the super call? PS. I'm working wit...
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How to concatenate properties from multiple JavaScript objects

...n Javascript. The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object. MDN documentation on Object.assign() var o1 = { a: 1 }; var o2 = { b: 2 }; var o3 = { c: 3 }; var...
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Count how many records are in a CSV Python?

...aranteed to be a fixed size, so the only way to count them is to read them all. – Martijn Pieters♦ Apr 19 '13 at 15:55 1 ...
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Is there a TRY CATCH command in Bash

... writing a shell script and need to check that a terminal app has been installed. I want to use a TRY/CATCH command to do this unless there is a neater way. ...
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Integrating the ZXing library directly into my Android application

...de so it hopefully can help others with the same problem as I had ;) Install Apache Ant - (See this YouTube video for config help) Download the ZXing source from ZXing homepage and extract it With the use of Windows Commandline (Run->CMD) navigate to the root directory of the downloaded zxing s...
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Is MATLAB OOP slow or am I doing something wrong?

...TLAB OOP , as a start I mimicked my C++'s Logger classes and I'm putting all my string helper functions in a String class, thinking it would be great to be able to do things like a + b , a == b , a.find( b ) instead of strcat( a b ) , strcmp( a, b ) , retrieve first element of strfind( a, b...
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Usage of __slots__?

What is the purpose of __slots__ in Python — especially with respect to when I would want to use it, and when not? 11 A...
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How do I detect whether a Python variable is a function?

... If this is for Python 2.x or for Python 3.2+, you can also use callable(). It used to be deprecated, but is now undeprecated, so you can use it again. You can read the discussion here: http://bugs.python.org/issue10518. You can do this with: callable(obj) If this is for Python 3.x but ...
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What's the difference between globals(), locals(), and vars()?

What is the difference between globals() , locals() , and vars() ? What do they return? Are updates to the results useful? ...