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To find whether a column exists in data frame or not
I have a data.frame with the name "abcframe"
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How to gzip all files in all sub-directories into one compressed file in bash
This post describes how to gzip each file individually within a directory structure. However, I need to do something slightly different. I need to produce one big gzip file for all files under a certain directory. I also need to be able to specify the output filename for the compressed file (e.g., ...
Add zero-padding to a string
How do I add "0" padding to a string so that my string length is always 4?
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What's a quick way to test to see a file exists?
I want to quickly check to see if a file exists in my iPhone app's Documents directory (or any path for that matter). I can enumerate through the directory's files, or I can try to open a specific file. What's the fastest way? I just need to know if the file is there or if it does not exist.
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setting multiple column using one update
How to set multiple columns of a table using update query in mysql?
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When does Java's Thread.sleep throw InterruptedException?
When does Java's Thread.sleep throw InterruptedException? Is it safe to ignore it? I am not doing any multithreading. I just want to wait for a few seconds before retrying some operation.
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Avoiding memory leaks with Scalaz 7 zipWithIndex/group enumeratees
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How to put a unicode character in XAML?
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How do I get Gridview to render THEAD?
How do I get the GridView control to render the <thead> <tbody> tags? I know .UseAccessibleHeaders makes it put <th> instead of <td> , but I cant get the <thead> to appear.
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How to drop multiple columns in postgresql
I want to drop 200 columns in my table in PostgreSQL. I tried:
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