Tutorial by Examples: o

As per the Go blog: Arrays do not need to be initialized explicitly; the zero value of an array is a ready-to-use array whose elements are themselves zeroed For example, myIntArray is initialized with the zero value of int, which is 0: var myIntArray [5]int // an array of five 0's: [0, 0,...

Creating a Scala function that receives an python RDD is easy. What you need to build is a function that get a JavaRDD[Any] import org.apache.spark.api.java.JavaRDD def doSomethingByPythonRDD(rdd :JavaRDD[Any]) = { //do something rdd.map { x => ??? } }

This part of development you should serialize the python RDD to the JVM. This process uses the main development of Spark to call the jar function. from pyspark.serializers import PickleSerializer, AutoBatchedSerializer rdd = sc.parallelize(range(10000)) reserialized_rdd = rdd._reserialize(Aut...

To call this code you should create the jar of your scala code. Than you have to call your spark submit like this: spark-submit --master yarn-client --jars ./my-scala-code.jar --driver-class-path ./my-scala-code.jar main.py This will allow you to call any kind of scala code that you need in your...

Sometimes, the straight forward loop cannot be entirely contained within the loop body. This is because, the loop needs to be primed by some statements B. Then, the iteration begins with some statements A, which are then followed by B again before looping. do_B(); while (condition) { do_A(); ...

Using many ECHO commands to create a batch file: ( echo echo hi, this is the date today echo date /T echo echo created on %DATE% echo pause >nul )>hi.bat The command interpreter treats the whole section in parenthesis as a single command, then saves all the output to hi.bat. ...

Ant provides some built-in properties Property NameValuebasedirthe absolute path of the project's basedirant.filethe absolute path of the buildfile.ant.versionthe version of Antant.project.default-targetthe name of the currently executing project's default targetant.project.namename of the projecta...

There are two ways to define models in sequelize; with sequelize.define(...), or sequelize.import(...). Both functions return a sequelize model object. 1. sequelize.define(modelName, attributes, [options]) This is the way to go if you'd like to define all your models in one file, or if you want to...

There are four ways to work with JavaScript plugins, Ember add-on Import JavaScript plugins globally Consume named AMD plugins Via ember-browserify

First, complete the installation and setup to connect your app to Firebase. Then from anywhere in your class, you can write: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRe...

Gradle (All Versions) This method works for all versions of gradle Add the buildscript code at the beginning of your build.gradle file. buildscript { repositories { maven { url "https://plugins.gradle.org/m2/" } } dependencies { classpath "org.example...

Basic Idea The notation used when describing the speed of your Python program is called Big-O notation. Let's say you have a function: def list_check(to_check, the_list): for item in the_list: if to_check == item: return True return False This is a simple function ...

Operations : Average Case (assumes parameters are randomly generated) Append : O(1) Copy : O(n) Del slice : O(n) Delete item : O(n) Insert : O(n) Get item : O(1) Set item : O(1) Iteration : O(n) Get slice : O(k) Set slice : O(n + k) Extend : O(k) Sort : O(n log n) Multiply : O(nk) x in...

A deque is a double-ended queue. class Deque: def __init__(self): self.items = [] def isEmpty(self): return self.items == [] def addFront(self, item): self.items.append(item) def addRear(self, item): self.items.insert(0,item) def removeFront(self): return self....

Operation : Average Case (assumes parameters generated randomly) : Worst case x in s : O(1) Difference s - t : O(len(s)) Intersection s&t : O(min(len(s), len(t))) : O(len(s) * len(t) Multiple intersection s1&s2&s3&...&sn : : (n-1) * O(l) where l is max(len(s1),...,len(sn)) s...

When using d3.request() or one of the convenience constructors (d3.json, d3.csv, d3.tsv, d3.html and d3.xml) there are many sources for error. There may be problems with the issued request or its response due to network errors, or the parsing might fail if the content is not well-formed. Within the...

Like page caching, action caching caches the whole page. The difference is that the request hits the Rails stack so before filters are run before the cache is served. It's extracted from Rails to actionpack-action_caching gem. A common example is caching of an action that requires authentication: ...

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

Decryption Code public static string Decrypt(string cipherText) { if (cipherText == null) return null; byte[] cipherBytes = Convert.FromBase64String(cipherText); using (Aes encryptor = Aes.Create()) { Rfc2898DeriveBytes pdb = ...

We can use command uname with various options to get complete details of running kernel. uname -a Linux df1-ws-5084 4.4.0-64-generic #85-Ubuntu SMP Mon Feb 20 11:50:30 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux As per man page here few more options Usage: uname [OPTION]... Print certain system inf...