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Traverse a list in reverse order in Python
... are reversed on the fly while traversing! This is an important feature of all these iteration functions (which all end on “ed”).
– Konrad Rudolph
Feb 9 '09 at 19:10
9
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Is there a benefit to defining a class inside another class in Python?
What I'm talking about here are nested classes. Essentially, I have two classes that I'm modeling. A DownloadManager class and a DownloadThread class. The obvious OOP concept here is composition. However, composition doesn't necessarily mean nesting, right?
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How do you query for “is not null” in Mongo?
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This will return all documents with a key called "IMAGE URL", but they may still have a null value.
db.mycollection.find({"IMAGE URL":{$exists:true}});
This will return all documents with both a key called "IMAGE URL" and a non-null value.
d...
std::unique_ptr with an incomplete type won't compile
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I find your first solution (adding the foo destructor) allows the class declaration itself to compile, but declaring an object of that type anywhere results in the original error ("invalid application of 'sizeof'...").
– Jeff Trull
Sep 30 '1...
Linux: copy and create destination dir if it does not exist
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oops, right. But then, test may be a bash builtin (especially if written as [[ -d "$d" ]]) and mkdir can not ;-)
– Michael Krelin - hacker
Oct 7 '09 at 17:00
1
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How do I write good/correct package __init__.py files
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__all__ is very good - it helps guide import statements without automatically importing modules
http://docs.python.org/tutorial/modules.html#importing-from-a-package
using __all__ and import * is redundant, only __all__ is nee...
A semantics for Bash scripts?
...patchwork together little scripts that appear to work. However, I don't really know what's going on, and I was hoping for a more formal introduction to Bash as a programming language. For example: What is the evaluation order? what are the scoping rules? What is the typing discipline, e.g. is ever...
How to test code dependent on environment variables using JUnit?
... value);
}
}
For Java 5 to 7 the library System Rules has a JUnit rule called EnvironmentVariables.
import org.junit.contrib.java.lang.system.EnvironmentVariables;
public class EnvironmentVariablesTest {
@Rule
public final EnvironmentVariables environmentVariables
= new EnvironmentVariab...
Forced naming of parameters in Python
...(10, forcenamed=20)
10 20
>>> foo(10, 20)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: foo() takes exactly 1 positional argument (2 given)
This can also be combined with **kwargs:
def foo(pos, *, forcenamed, **kwargs):
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How to get instance variables in Python?
Is there a built-in method in Python to get an array of all a class' instance variables? For example, if I have this code:
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