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Check existence of directory and create if doesn't exist
I often find myself writing R scripts that generate a lot of output. I find it cleaner to put this output into it's own directory(s). What I've written below will check for the existence of a directory and move into it, or create the directory and then move into it. Is there a better way to approach...
if…else within JSP or JSTL
I want to output some HTML code based on some condition in a JSP file.
13 Answers
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How do I know that the UICollectionView has been loaded completely?
I have to do some operation whenever UICollectionView has been loaded completely, i.e. at that time all the UICollectionView's datasource / layout methods should be called. How do I know that?? Is there any delegate method to know UICollectionView loaded status?
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How to make an immutable object in Python?
Although I have never needed this, it just struck me that making an immutable object in Python could be slightly tricky. You can't just override __setattr__ , because then you can't even set attributes in the __init__ . Subclassing a tuple is a trick that works:
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MySQL and GROUP_CONCAT() maximum length
I'm using GROUP_CONCAT() in a MySQL query to convert multiple rows into a single string.
However, the maximum length of the result of this function is 1024 characters.
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Like Operator in Entity Framework?
We're trying to implement the "LIKE" operator in Entity Framework for our entities with string fields, but it doesn't appear to be supported. Has anyone else tried to do something like this?
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How to find unused images in an Xcode project?
Has anyone a one-line to find unused images in an Xcode project? (Assuming all the files are referenced by name in code or the project files - no code generated file names.)
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How can I create a keystore?
What are the steps to create a keystore for android?
11 Answers
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Android ListView headers
I have ListView that has some kind of events on it. Events are sorted by day, and I would like to have header with date on it for every day, and then events listen below.
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Are Exceptions in C++ really slow
I was watching Systematic Error Handling in C++—Andrei Alexandrescu he claims that Exceptions in C++ are very very slow.
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