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Can dplyr package be used for conditional mutating?
Can the mutate be used when the mutation is conditional (depending on the values of certain column values)?
5 Answers
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List columns with indexes in PostgreSQL
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Create some test data...
create table test (a int, b int, c int, constraint pk_test primary key(a, b));
create table test2 (a int, b int, c int, constraint uk_test2 unique (b, c));
create table test3 (a int, b int, c int, constraint uk_test3b unique (b), cons...
Parse JSON in C#
...ON data from the Google AJAX Search API. I have this URL and I'd like to break it down so that the results are displayed. I've currently written this code, but I'm pretty lost in regards of what to do next, although there are a number of examples out there with simplified JSON strings.
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How to find the JVM version from a program?
...u need.
You can also use JMX if you want:
ManagementFactory.getRuntimeMXBean().getVmVersion()
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How do I turn a python datetime into a string, with readable format date?
...on docs documents the different formats it accepts:
Python 2: strftime() Behavior
Python 3: strftime() Behavior
For this specific example, it would look something like:
my_datetime.strftime("%B %d, %Y")
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Appending a vector to a vector [duplicate]
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a.insert(a.end(), b.begin(), b.end());
or
a.insert(std::end(a), std::begin(b), std::end(b));
The second variant is a more generically applicable solution, as b could also be an array. However, it requires C++11. If you want to work with ...
Converting a list to a set changes element order
...onverting a list to set the order of elements is changed and is sorted by character.
11 Answers
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Is it possible to use 'else' in a list comprehension? [duplicate]
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The syntax a if b else c is a ternary operator in Python that evaluates to a if the condition b is true - otherwise, it evaluates to c. It can be used in comprehension statements:
>>> [a if a else 2 for a in [0,1,0,3]]
[2, 1, 2, 3]...
What causes and what are the differences between NoClassDefFoundError and ClassNotFoundException?
What is the difference between NoClassDefFoundError and ClassNotFoundException ?
15 Answers
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PHP Redirect with POST data
... this topic, and there are some experts who have said that it is not possible , so I would like to ask for an alternative solution.
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