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What is the most efficient string concatenation method in python?
Is there any efficient mass string concatenation method in Python (like StringBuilder in C# or StringBuffer in Java)? I found following methods here :
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JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images
Digital camera photos are often saved as JPEG with an EXIF "orientation" tag. To display correctly, images need to be rotated/mirrored depending on which orientation is set, but browsers ignore this information rendering the image. Even in large commercial web apps, support for EXIF orientation can ...
What's the simplest way to test whether a number is a power of 2 in C++?
I need a function like this:
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How do I replace NA values with zeros in an R dataframe?
I have a data frame and some columns have NA values.
21 Answers
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Dynamically select data frame columns using $ and a character value
I have a vector of different column names and I want to be able to loop over each of them to extract that column from a data.frame. For example, consider the data set mtcars and some variable names stored in a character vector cols . When I try to select a variable from mtcars using a dynamic s...
Is “argv[0] = name-of-executable” an accepted standard or just a common convention?
When passing argument to main() in a C or C++ application, will argv[0] always be the name of the executable? Or is this just a common convention and not guaranteed to be true 100% of the time?
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Removing leading zeroes from a field in a SQL statement
I am working on a SQL query that reads from a SQLServer database to produce an extract file. One of the requirements to remove the leading zeroes from a particular field, which is a simple VARCHAR(10) field. So, for example, if the field contains '00001A', the SELECT statement needs to return the...
Are members of a C++ struct initialized to 0 by default?
I have this struct :
8 Answers
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SQL keys, MUL vs PRI vs UNI
What is the difference between MUL , PRI and UNI in MySQL?
4 Answers
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How to split a string and assign it to variables
In Python it is possible to split a string and assign it to variables:
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