title: error ... ImportError: No module named cassandra.cluster
body: <p>I am trying to follow the below video about write-paths and when i use the sample student-files that are provided i get below error....i am really new to cassandra and trying to figure out why the excerise file not work....i have provided the error that i get(ImportError: No module named cassandra.cluster) and also the .sh and .py file...any help is appriciated...</p>
  
  <p><a href="https://academy.datastax.com/courses/understanding-cassandra-write-path/understanding-data-files" rel="nofollow">https://academy.datastax.com/courses/understanding-cassandra-write-path/understanding-data-files</a></p>
  
  <pre><code>    cass@cass:~/student-files/write-path/exercise-1$ ccm list
   *demo_1node
  cass@cass:~/student-files/write-path/exercise-1$
  cass@cass:~/student-files/write-path/exercise-1$ ccm status
  Cluster: 'demo_1node'
  ---------------------
  node1: UP
  cass@cass:~/student-files/write-path/exercise-1$
  cass@cass:~/student-files/write-path/exercise-1$ ./write_data.sh 300000
  Traceback (most recent call last):
    File "./write_data.py", line 5, in &lt;module&gt;
      from cassandra.cluster import Cluster
  ImportError: No module named cassandra.cluster
  cass@cass:~/student-files/write-path/exercise-1$
  
  cass@cass:~/student-files/write-path/exercise-1$ cat write_data.sh
  #!/bin/bash
  
  if [ $# -ne 1 ]; then
    echo "Usage: write_data.sh &lt;number of keys&gt;"
    exit 0
  fi
  
  if [ `ccm status | grep "node1: UP" | wc -l` -ne 1 ]; then
    echo "Cassandra cluster not up"
    exit 0
  fi
  
  ./write_data.py $1
  cass@cass:~/student-files/write-path/exercise-1$
  cass@cass:~/student-files/write-path/exercise-1$ cat write_data.py
  #!/usr/bin/python
  
  # This Python script will insert a number of keys into
  # musicdb.user
  from cassandra.cluster import Cluster
  from random import randint
  from sets import Set
  from uuid import uuid4
  import os,sys,time,binascii
  
  if len(sys.argv) &lt; 2:
      print "Usage: python.py &lt;number of keys&gt;"
      sys.exit()
  
  cluster = Cluster(['127.0.0.1'])
  session = cluster.connect()
  
  insert_row_prepare = session.prepare("INSERT INTO musicdb.user (id,preferences) VALUES(?,?)")
  
  quarter=int(int(sys.argv[1])/4)
  half=int(int(sys.argv[1])/2)
  three_quarter=int(int(sys.argv[1])/4)+int(int(sys.argv[1])/2)
  
  for x in range(0,int(sys.argv[1])):
    id = uuid4()
    set = Set([binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),
               binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),
               binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),
               binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100)),binascii.b2a_hex(os.urandom(100))])
    insert_row_bind = insert_row_prepare.bind([id,set])
    session.execute(insert_row_bind)
  
    if (x+1) == int(sys.argv[1]):
      print "100% completed - " + str(x+1) + " rows inserted."
    elif (x+1) == quarter:
      print "25% completed - " + str(x+1) + " rows inserted."
    elif (x+1) == half:
      print "50% completed - " + str(x+1) + " rows inserted."
    elif (x+1) == three_quarter:
      print "75% completed - " + str(x+1) + " rows inserted."
  
  time.sleep(1)
  cluster.shutdown()
  cass@cass:~/student-files/write-path/exercise-1$
  </code></pre>