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Unique fields that allow nulls in Django

...aggregates. It has been replaced with from_db_value(). Note that the new approach does not call the to_python() method on assignment as was the case with SubfieldBase. Therefore, as suggested by the from_db_value() documentation and this example, this solution must be changed to: class CharNull...
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What do 'real', 'user' and 'sys' mean in the output of time(1)?

... time; User and Sys refer to CPU time used only by the process. Real is wall clock time - time from start to finish of the call. This is all elapsed time including time slices used by other processes and time the process spends blocked (for example if it is waiting for I/O to complete). User is t...
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How to concatenate and minify multiple CSS and JavaScript files with Grunt.js (0.3.x)

...change the structure of your project. If doing the latter, you could put all your sources under ./src and your built files under ./dest src ├── css │   ├── 1.css │   ├── 2.css │   └── 3.css └── js ├── 1.js ├── 2.js └── 3.js ...
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How to create a zip archive of a directory in Python?

...e. The documentation tells you what functions are available, but doesn't really explain how you can use them to zip an entire directory. I think it's easiest to explain with some example code: #!/usr/bin/env python import os import zipfile def zipdir(path, ziph): # ziph is zipfile handle f...
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What should I set JAVA_HOME environment variable on macOS X 10.6?

...a_home) I haven't experienced any problems with that technique. Occasionally I do have to change the value of JAVA_HOME to an earlier version of Java. For example, one program I'm maintaining requires 32-bit Java 5 on OS X, so when using that program, I set JAVA_HOME by running: export JAVA_HOM...
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How to sort a list of objects based on an attribute of the objects?

...is a need to sort by multiple fields, it could be achieved by consecutive calls to sort(), because python is using stable sort algorithm. – zzz777 Feb 23 at 14:41 add a commen...
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Ship an application with a database

... for creating and updating databases. One is to create a database externally, then place it in the assets folder of the project and then copy the entire database from there. This is much quicker if the database has a lot of tables and other components. Upgrades are triggered by changing the dat...
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Can you find all classes in a package using reflection?

Is it possible to find all classes or interfaces in a given package? (Quickly looking at e.g. Package , it would seem like no.) ...
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Creating an abstract class in Objective-C

I'm originally a Java programmer who now works with Objective-C. I'd like to create an abstract class, but that doesn't appear to be possible in Objective-C. Is this possible? ...
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How to host a Node.Js application in shared hosting [closed]

How to host a Node.Js application in a shared hosting 5 Answers 5 ...