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Apache Spark: map vs mapPartitions?
...lize(List("dog", "salmon", "salmon", "rat", "elephant"), 3)
val b = a.map(_.length)
val c = a.zip(b)
c.collect
res0: Array[(String, Int)] = Array((dog,3), (salmon,6), (salmon,6), (rat,3), (elephant,8))
mapPartitions
This is a specialized map that is called only once for each partition.
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Sort JavaScript object by key
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@Phil_1984_ This answer and top voted answer are very different. OP's question was how to sort an object literal. Top voted answer says you can't, then gives a workaround by storing sorted keys in an array, then iterating and prin...
Very simple log4j2 XML configuration file using Console and File appender
...gt;
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
</Console>
<File name="MyFile" fileName="all.log" immediateFlush="false" append="false">
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Equation (expression) parser with precedence?
...is four function calculator:
http://www.gnu.org/software/bison/manual/html_node/Infix-Calc.html
Look at the generated code, and see that this is not as easy as it sounds. Also, the advantages of using a tool like Bison are 1) you learn something (especially if you read the Dragon book and learn ab...
How does a public key verify a signature?
...autl -encrypt -inkey public.pem -pubin -in message.txt -out message_enc_pub.ssl
openssl rsautl -decrypt -inkey private.pem -in message_enc_pub.ssl -out message_pub.txt
xxd message_enc_pub.ssl # Print the binary contents of the encrypted message
cat message_pub.txt # Print the decrypted...
Adding the “Clear” Button to an iPhone UITextField
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func clear_btn(box_is : UITextField){
box_is.clearButtonMode = .always
if let clearButton = box_is.value(forKey: "_clearButton") as? UIButton {
let templateImage = clearButton.imageView?.image?.withRenderingMode(.alway...
What does cmd /C mean? [closed]
...here's also a command to "pause" the cmd window after output: "cmd /c file_name & PAUSE" it is bit different from cmd /k
– Gourav
Sep 5 '15 at 19:34
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What resources exist for Database performance-tuning? [closed]
...tabase, this guide may also help.
http://download.oracle.com/docs/cd/B28359_01/server.111/b28274/toc.htm
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Split string, convert ToList() in one line
...ers
.Split(',')
.Where(x => int.TryParse(x, out _))
.Select(int.Parse)
.ToList();
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Initialise a list to a specific length in Python [duplicate]
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or [{} for _ in range(10)] to avoid lint warnings
– Martin Konecny
May 3 '13 at 1:22
7
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