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How to find all the subclasses of a class given its name?
...'s module hasn't been imported yet - then that subclass doesn't exist yet, and __subclasses__ won't find it.
You mentioned "given its name". Since Python classes are first-class objects, you don't need to use a string with the class's name in place of the class or anything like that. You can just...
Semicolons superfluous at the end of a line in shell scripts?
...lons at the end of a line are superfluous, since the newline is also a command separator. case specifically needs double semicolons at the end of the last command in each pattern block; see help case for details.
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Unignore subdirectories of ignored directories in Git
... want to include zip files. I added this line to that project's .gitignore and it works great!: !*.zip
– Jinghao Shi
Mar 21 '15 at 3:44
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Show a PDF files in users browser via PHP/Perl
...n why I use cgi to show the pdf is I want to track the clicks for the pdf, and cloak the real location of the saved pdf.
5 ...
Android Studio: Where is the Compiler Error Output Window?
When I 'Run' my project in Android Studio, in the 'Messages' window, I get:
15 Answers
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What does a lazy val do?
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In contrast to a method (defined with def) a lazy val is executed once and then never again. This can be useful when an operation takes long time to complete and when it is not sure if it is later used.
scala> class X { val x = { Thread.sleep(2000); 15 } }
defined class X
scala> class Y ...
How does MongoDB sort records when no sort order is specified?
...ementation detail. Maintaining order is extra overhead for storage engines and MongoDB's API does not mandate predictability outside of an explicit sort() or the special case of fixed-sized capped collections which have associated usage restrictions. For typical workloads it is desirable for the sto...
typedef fixed length array
...used as a function argument, it will be passed by reference, not by value, and the sizeof for it will then be wrong.
A better solution would be
typedef struct type24 { char x[3]; } type24;
You probably also want to be using unsigned char instead of char, since the latter has implementation-defin...
Prevent screen rotation on Android
...h I would like to prevent from rotating because I'm starting an AsyncTask, and screen rotation makes it restart.
15 Answers...
How do you use script variables in psql?
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Postgres variables are created through the \set command, for example ...
\set myvariable value
... and can then be substituted, for example, as ...
SELECT * FROM :myvariable.table1;
... or ...
SELECT * FROM table1 WHERE :myvariable IS NULL;
edit: As of psql 9.1, varia...