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How can I use if/else in a dictionary comprehension?
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@Marcin's answer covers it all, but just in case someone wants to see an actual example, I add two below:
Let's say you have the following dictionary of sets
d = {'key1': {'a', 'b', 'c'}, 'key2': {'foo', 'bar'}, 'key3': {'so', 'sad'}}
and you want ...
An error occurred while installing pg (0.17.1), and Bundler cannot continue
I just installed Rails 4.0.2 and when creating a new app, in the bundle stage I get:
16 Answers
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How do I install Python OpenCV through Conda?
I'm trying to install OpenCV for Python through Anaconda , but I can't seem to figure this out.
41 Answers
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Correct way to close nested streams and writers in Java [duplicate]
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I usually do the following. First, define a template-method based class to deal with the try/catch mess
import java.io.Closeable;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
public abstract cl...
Best XML Parser for PHP [duplicate]
...saves on memory. You pay for that with not being able to use XPath.
Personally, I find SimpleXml quite limiting (hence simple) in what it offers over DOM. You can switch between DOM and SimpleXml easily though, but I usually dont bother and go the DOM route directly. DOM is an implementation of the...
what is the difference between 'transform' and 'fit_transform' in sklearn
...is meant for when you have already computed PCA, i.e. if you have already called its .fit method.
In [12]: pc2 = RandomizedPCA(n_components=3)
In [13]: pc2.transform(X) # can't transform because it does not know how to do it.
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“:” (colon) in C struct - what does it mean? [duplicate]
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Those are bit fields. Basically, the number after the colon describes how many bits that field uses. Here is a quote from MSDN describing bit fields:
The constant-expression specifies the width of the field in bits. The
type-specifier for the dec...
Representing Directory & File Structure in Markdown Syntax [closed]
...se ASCII to build the structures, so your example structure becomes
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+-- _config.yml
+-- _drafts
| +-- begin-with-the-crazy-ideas.textile
| +-- on-simplicity-in-technology.markdown
+-- _includes
| +-- footer.html
| +-- header.html
+-- _layouts
| +-- default.html
| +-- post.html
+-- _po...
Do declared properties require a corresponding instance variable?
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In your interface, you can formally declare an instance variable between the braces, or via @property outside the braces, or both. Either way, they become attributes of the class. The difference is that if you declare @property, then you can implement usin...
In Eclipse, what can cause Package Explorer “red-x” error-icon when all Java sources compile without
I'm using Eclipse for Java development. All my sources compile fine and the resulting application compiles fine. However, I keep getting an "red-x" error notification in the Package Explorer.
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