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What makes Lisp macros so special?

...le syntax for a common case. The line divisibleByTwo = [x for x in range(10) if x % 2 == 0] yields a list containing all even numbers between 0 and 9. Back in the Python 1.5 days there was no such syntax; you'd use something more like this: divisibleByTwo = [] for x in range( 10 ): if x % 2 ...
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Replacing blank values (white space) with NaN in pandas

... 207 I think df.replace() does the job, since pandas 0.13: df = pd.DataFrame([ [-0.532681, 'foo...
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What does the `#` operator mean in Scala?

...t; val a1 = new A a1: A = A@1497b7b1 scala> val a2 = new A a2: A = A@2607c28c scala> a2.f(new a1.B) <console>:11: error: type mismatch; found : a1.B required: a2.B a2.f(new a1.B) ^ scala> a2.g(new a1.B) Got a B. ...
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Using helpers in model: how do I include helper dependencies?

...om a text area. Following the advice from http://blog.caboo.se/articles/2008/8/25/sanitize-your-users-html-input , I'm cleaning up the input in the model before saving to database, using the before_validate callback. ...
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What are all the user accounts for IIS/ASP.NET and how do they differ?

Under Windows Server 2008 with ASP.NET 4.0 installed there is a whole slew of related user accounts, and I can't understand which one is which, how to they differ, and which one is REALLY the one that my app runs under. Here's a list: ...
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How to count TRUE values in a logical vector

... answered Feb 3 '10 at 12:29 MarekMarek 43.9k1313 gold badges8484 silver badges114114 bronze badges ...
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What is the purpose of a plus symbol before a variable?

... | edited Apr 10 '19 at 13:32 Daniel W. 24.8k88 gold badges7070 silver badges114114 bronze badges ...
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Create dynamic URLs in Flask with url_for()

... answered Sep 20 '11 at 0:02 FogleBirdFogleBird 61.9k2323 gold badges117117 silver badges127127 bronze badges ...
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Referencing system.management.automation.dll in Visual Studio

...n on Nuget System.Management.Automation.dll on NuGet, newer package from 2015, not unlisted as the previous one! Microsoft PowerShell team packages un NuGet Update: package is now owned by PowerShell Team. Huzzah! share ...
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How to make Twitter Bootstrap tooltips have multiple lines?

...ally be actual newlines. Alternatively, you can use encoded newlines 
, but that's probably even less desirable than using <br>'s. share | improve this answer | ...