DataStax-Examples/quickstart-python

A basic Python demo CRUD application using the DataStax Python Driver for Apache Cassandra.Run the quickstart_complete.py file if you want to skip the exercise and run the application with the complete code.Contributors: Rebecca MillsObjectivesTo demonstrate how to perform basic CRUD operations with the DataStax Python Driver.The intent is to help users get up and running quickly with the driver.How this Sample WorksThis project walks through basic CRUD operations using Cassandra. The demo application will first insert a row of user data, select that same row back out, update the row and finally delete the user. The README includes the code snippets to be filled in to the main application code to complete the functionality.Project Layoutquickstart.py - main application file with space to fill in CRUD operation codeusers.cql - Use this file to create the schemaPrerequisitesA running instance of Apache Cassandra® 2.1+Python 2.7, 3.4, 3.5, or 3.6.Use Pip to install the driver: pip install cassandra-driverWe highly recommend to use a virtualenvCreate the keyspace and tableThe users.cql file provides the schema used for this project:CREATE KEYSPACE demo WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'};CREATE TABLE demo.users ( lastname text PRIMARY KEY, age int, city text, email text, firstname text);Connect to your clusterAll of our code is contained in the quickstart.py file.The create_connection() function connects to our cluster.By default, Cluster() will try to connect to 127.0.0.1 (localhost). Replace with your own contact point(s) if necessary.def create_connection(): # TO DO: Fill in your own contact point cluster = Cluster(['127.0.0.1']) return cluster.connect('demo')CRUD OperationsFill the code in the functions that will add a user, get a user, update a user and delete a user from the table with the driver.INSERT a userdef set_user(session, lastname, age, city, email, firstname): # TO DO: execute SimpleStatement that inserts one user into the table session.execute("INSERT INTO users (lastname, age, city, email, firstname) VALUES (%s,%s,%s,%s,%s)", [lastname, age, city, email, firstname])SELECT a userdef get_user(session, lastname): # TO DO: execute SimpleStatement that retrieves one user from the table # TO DO: print firstname and age of user result = session.execute("SELECT * FROM users WHERE lastname = %s", [lastname]).one() print result.firstname, result.ageUPDATE a user's agedef update_user(session, new_age, lastname): # TO DO: execute SimpleStatement that updates the age of one user session.execute("UPDATE users SET age =%s WHERE lastname = %s", [new_age, lastname])DELETE a userdef delete_user(session, lastname): # TO DO: execute SimpleStatement that deletes one user from the table session.execute("DELETE FROM users WHERE lastname = %s", [lastname])LicenseCopyright 2019 Rebecca MillsLicensed under the Apache License, Version 2.0 (the "License");you may not use this file except in compliance with the License.You may obtain a copy of the License athttp://www.apache.org/licenses/LICENSE-2.0Unless required by applicable law or agreed to in writing, softwaredistributed under the License is distributed on an "AS IS" BASIS,WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.See the License for the specific language governing permissions andlimitations under the License.