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How to use filter, map, and reduce in Python 3
filter , map , and reduce work perfectly in Python 2. Here is an example:
7 Answers
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Automatically expanding an R factor into a collection of 1/0 indicator variables for every factor le
I have an R data frame containing a factor that I want to "expand" so that for each factor level, there is an associated column in a new data frame, which contains a 1/0 indicator. E.g., suppose I have:
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How to select a single field for all documents in a MongoDB collection?
... MongoDB, I have a student collection with 10 records having fields name and roll . One record of this collection is:
1...
What is the difference between a cer, pvk, and pfx file?
What is the difference between a cer, pvk, and pfx file? Also, which files do I keep and which am I expected to give to my counter-parties?
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Why is null an object and what's the difference between null and undefined?
...n short; undefined is where no notion of the thing exists; it has no type, and it's never been referenced before in that scope; null is where the thing is known to exist, but it's not known what the value is.
One thing to remember is that null is not, conceptually, the same as false or "" or such, e...
Making a Location object in Android with latitude and longitude values
I have a program in which latitude and longitude values of a location are stored in a database, which I download.
3 Answer...
Javascript equivalent of Python's zip function
...0col0","row1col0"],
["row0col1","row1col1"],
["row0col2","row1col2"]]
(and FizzyTea points out that ES6 has variadic argument syntax, so the following function definition will act like python, but see below for disclaimer... this will not be its own inverse so zip(zip(x)) will not equal x; thoug...
What is the pythonic way to detect the last element in a 'for' loop?
I'd like to know the best way (more compact and "pythonic" way) to do a special treatment for the last element in a for loop. There is a piece of code that should be called only between elements, being suppressed in the last one.
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Why not use java.util.logging?
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Disclaimer: I am the founder of log4j, SLF4J and logback projects.
There are objective reasons for preferring SLF4J. For one, SLF4J allows the end-user the liberty to choose the underlying logging framework. In addition, savvier users tend to prefer logback which offe...
What is the difference between currying and partial application?
...rn value is a closure of lambda(z){z(x(y))} with passed-in the values of x and y to f(x,y).
One way to use partial application is to define functions as partial applications of generalized functions, like fold:
function fold(combineFunction, accumulator, list) {/* ... */}
function sum = curry...