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How can I use if/else in a dictionary comprehension?
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@Marcin's answer covers it all, but just in case someone wants to see an actual example, I add two below:
Let's say you have the following dictionary of sets
d = {'key1': {'a', 'b', 'c'}, 'key2': {'foo', 'bar'}, 'key3': {'so', 'sad'}}
and you want ...
What does static_assert do, and what would you use it for?
...fined (as one would expect in a C++ library).
Contrast with having to actually compile SomeLibrary and your code, link everything, and run the executable only then to find out that you spent 30 minutes compiling an incompatible version of SomeLibrary.
@Arak, in response to your comment: yes, you ...
Get keys from HashMap in Java
...HashMap contains more than one key. You can use keySet() to get the set of all keys.
team1.put("foo", 1);
team1.put("bar", 2);
will store 1 with key "foo" and 2 with key "bar". To iterate over all the keys:
for ( String key : team1.keySet() ) {
System.out.println( key );
}
will print "foo"...
importing pyspark in python shell
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If it prints such error:
ImportError: No module named py4j.java_gateway
Please add $SPARK_HOME/python/build to PYTHONPATH:
export SPARK_HOME=/Users/pzhang/apps/spark-1.1.0-bin-hadoop2.4
export PYTHONPATH=$SPARK_HOME/python:$SPARK_HOME/python/build:$PYTHONPATH
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Defining a function with multiple implicit arguments in Scala
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They must all go in one parameter list, and this list must be the last one.
def myfun(arg:String)(implicit p1: String, p2:Int)={}
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What is the strict aliasing rule?
...n(void)
{
// Get a 32-bit buffer from the system
uint32_t* buff = malloc(sizeof(Msg));
// Alias that buffer through message
Msg* msg = (Msg*)(buff);
// Send a bunch of messages
for (int i = 0; i < 10; ++i)
{
msg->a = i;
msg->b = i+1;...
Java Error opening registry key
...er removing the "java" executables from my system32 folder, I had to reinstall the JRE. After that, my problem was solved. Thanks for the starting point.
– dangowans
Dec 24 '13 at 18:31
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In STL maps, is it better to use map::insert than []?
...els natural and is clear to read whereas he preferred map.insert(std::make_pair(key, value)) .
13 Answers
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How to write into a file in PHP?
...on like:
file_put_contents($filename, $content);
which is identical to calling fopen(), fwrite(), and fclose() successively to write data to a file.
Docs: file_put_contents
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How to get one value at a time from a generator function in Python?
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In Python <= 2.5, use gen.next(). This will work for all Python 2.x versions, but not Python 3.x
In Python >= 2.6, use next(gen). This is a built in function, and is clearer. It will also work in Python 3.
Both of these end up calling a specially named function, next(), wh...