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Should functions return null or an empty object?
...g data from functions. Is it better to return a Null or an empty object? And why should one do one over the other?
31 Ans...
Clojure differences between Ref, Var, Agent, Atom, with examples
...here to use Ref, Var, Agent, Atom. I read book, but, still couldn't understand the real world examples.
5 Answers
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How to set up Spark on Windows?
...s guide: http://spark.apache.org/docs/latest/building-spark.html
Download and install Maven, and set MAVEN_OPTS to the value specified in the guide.
But if you're just playing around with Spark, and don't actually need it to run on Windows for any other reason that your own machine is running Wind...
How to deal with SettingWithCopyWarning in Pandas?
I just upgraded my Pandas from 0.11 to 0.13.0rc1. Now, the application is popping out many new warnings. One of them like this:
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SimpleTest vs PHPunit
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This question is quite dated but as it is still getting traffic and answers I though I state my point here again even so I already did it on some other (newer) questions.
I'm really really baffled that SimpleTest still is considered an alternative to phpunit. Maybe i'm just misinformed bu...
When would you use a WeakHashMap or a WeakReference?
...mplementation of so I'm trying to figure out what the use case for them is and how the implementation would work. When have you needed to use a WeakHashMap or WeakReference and how was it used?
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Why can't I use float value as a template parameter?
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The current C++ standard does not allow float (i.e. real number) or character string literals to be used as template non-type parameters. You can of course use the float and char * types as normal arguments.
Perhaps the author is using a com...
How to create a numpy array of all True or all False?
...s very easily:
e.g. numpy.ones((2, 2)) or numpy.zeros((2, 2))
Since True and False are represented in Python as 1 and 0, respectively, we have only to specify this array should be boolean using the optional dtype parameter and we are done.
numpy.ones((2, 2), dtype=bool)
returns:
array([[ True, ...
Shards and replicas in Elasticsearch
I am trying to understand what shard and replica is in Elasticsearch, but I didn't manage to understand it. If I download Elasticsearch and run the script, then from what I know I have started a cluster with a single node. Now this node (my PC) have 5 shards (?) and some replicas (?).
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How to validate phone numbers using regex
...ogether a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:
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