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List changes unexpectedly after assignment. How do I clone or copy it to prevent this?
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With new_list = my_list, you don't actually have two lists. The assignment just copies the reference to the list, not the actual list, so both new_list and my_list refer to the same list after the assignment.
To actually copy the list, you have various possibilit...
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...
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 to load local html file into UIWebView
...le into my UIWebView but it won't work. Here's the stage: I have a folder called html_files in my project. Then I created a webView in interface builder and assigned an outlet to it in the viewController. This is the code I'm using to append the html file:
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Is it safe to parse a /proc/ file?
.../proc/mounts was a consistent snapshot.
For example:
/proc/uptime is totally atomic, as someone mentioned in another answer -- but only since Linux 2.6.30, which is less than two years old. So even this tiny, trivial file was subject to a race condition until then, and still is in most enterpris...
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...
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 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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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...