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Python Set Operations Explained: From Theory to Real-Time Applications

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A  set  in Python is an unordered collection of unique elements. It is useful when storing distinct values and performing operations like union, intersection, or difference. Real-Time Example: Removing Duplicate Customer Emails in a Marketing Campaign Imagine you are working on an email marketing campaign for your company. You have a list of customer emails, but some are duplicated. Using a set , you can remove duplicates efficiently before sending emails. Code Example: # List of customer emails (some duplicates) customer_emails = [ "alice@example.com" , "bob@example.com" , "charlie@example.com" , "alice@example.com" , "david@example.com" , "bob@example.com" ] # Convert list to a set to remove duplicates unique_emails = set (customer_emails) # Convert back to a list (if needed) unique_email_list = list (unique_emails) # Print the unique emails print ( "Unique customer emails:" , unique_email_list) Ou...
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How to Setup Hadoop Cluster Top Ideas

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Hadoop cluster setup in Centos Operating System explained in this post. So you can install CentOs either in your Laptop or in Virtual Machine.
Hadoop cluster setup proces
Hadoop Cluster Setup Process

9 Steps Process to Setup Hadoop Cluster

Step 1:  Installing Sun Java on Linux. Commands to execute for the same:
sudo apt-add-repository ppa:flexiondotorg/java
sudo apt-get update
sudo apt-get install sun-java6-jre sun-java6-plugin
sudo update-java-alternatives -s java-6-sun

Step 2:  Create Hadoop User. Commands to execute for the same:
$sudo addgroup hadoop
$sudo adduser —ingroup hadoop hduser

Step 3:  Install SSH Server if not already present. Commands are:
$ sudo apt-get install openssh-server
$ su - hduser
$ ssh-keygen -t rsa -P ""
$ cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys

Step 4:  Installing Hadoop. Commands for the same are:
$wget http://www.eng.lsu.edu/mirrors/apache/hadoop/core/hadoop-0.22.0/hadoop-0.22.0.tar.gz
$ cd /home/hduser
$ tar xzf hadoop-0.22.2.tar.gz
$ mv hadoop-0.22.2 hadoop

Step 5:  Edit .bashrc. Commands:
# Set Hadoop-related environment variables
export HADOOP_HOME=/home/hduser/hadoop
# Set JAVA_HOME (we will also configure JAVA_HOME directly for Hadoop later on)
export JAVA_HOME=/usr/lib/jvm/java-6-sun

Step 6:  Update hadoop-env.sh
Here we need to only update the JAVA_HOME variable, we just need to open the file from text editor.
$vi /home/hduser/hadoop/conf/hadoop-env.sh
And update the following:
export JAVA_HOME=/usr/lib/jvm/java-6-sun

Step 7:  Update the files residing in the conf folder.  The three main files are:
Core-site.xml
Mapred-site.xml
Hdfs-site.xml
Here we need to change the value of namenode and jobtracker to where we want to run.

Step 8:  Start the hadoop cluster, using command.
Start-all.sh

Step 9:  Check if all the processes are up and running, using command:
Jps
That’s it. The cluster should be up and running with the following 5 processes:
  • NameNode
  • SecondaryNameNode
  • DataNode
  • JobTracker
  • TaskTracker
If we see all these processes, it means our installation is successful and the cluster is up and running.

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