INFORMATICS PRACTICES

INFORMATICS PRACTICESTextbookforClass XI2020-21Prelims.indd 109-Aug-19 2:28:21 PM

ISBN 978-93-5292-148-5First EditionAugust 2019 Shravana 1941PD 50T BS National Council of EducationalResearch and Training, 2019ALL RIGHTS RESERVED No part of this publication may be reproduced, stored in aretrieval system or transmitted, in any form or by any means,electronic, mechanical, photocopying, recording or otherwisewithout the prior permission of the publisher. This book is sold subject to the condition that it shall not, byway of trade, be lent, re-sold, hired out or otherwise disposedof without the publisher’s consent, in any form of binding orcover other than that in which it is published. The correct price of this publication is the price printed onthis page, Any revised price indicated by a rubber stamp orby a sticker or by any other means is incorrect and shouldbe unacceptable.OFFICES OF THE PUBLICATIONDIVISION, NCERT140.00NCERT CampusSri Aurobindo MargNew Delhi 110 016Phone : 011-26562708108, 100 Feet RoadHosdakere Halli ExtensionBanashankari III StageBengaluru 560 085Phone : 080-26725740Navjivan Trust BuildingP.O.NavjivanAhmedabad 380 014Phone : 079-27541446CWC CampusOpp. Dhankal Bus StopPanihatiKolkata 700 114Phone : 033-25530454CWC ComplexMaligaonGuwahati 781 021Phone : 0361-2674869Publication TeamPrinted on 80 GSM paper with NCERTwatermarkPublished at the Publication Divisionby the Secretary, National Councilof Educational Research andTraining, Sri Aurobindo Marg, NewDelhi 110016 and printed at SwanPress, 308 & 309, Sector-7 Manesar,Gurugram - 122050, Haryana.Head, PublicationDivision: M. Siraj AnwarChief Editor: Shveta UppalChief Business Manager : Bibash Kumar DasChief Production Officer : Arun ChitkaraEditor: Bijnan SutarProduction Assistant: Mukesh GaurCover Design and LayoutMeetu Sharma (Contractul)2020-21Prelims.indd 209-Aug-19 2:28:21 PM

ForewordInformation Technology has continuously been crossing the barriersof access and communication and reaching more and more people.The number of internet users in India has been on the rise. Thetremendous growth in computer science, telecommunicationsand information technology has resulted in automation of varioustasks and contributed to the ease of living. Technology has madecontinuous inroads into diverse areas — be it business, commerce,science, sports, health, transportation or education. Today, we areliving in an interconnected world where computer based applicationsinfluence the way we learn, communicate, commute, or even socialise.With so many users of information and communicationtechnology (ICT), huge volumes of data are continuously generatedat an unprecedented rate. Many innovative business models arebeing evolved which utilise such data to reach potential customersin a more targeted way. Government agencies are also using datato deliver services and fast track progress of different programmes,strengthen accountability and to make more informed decisions.This has been creating better opportunities for our youth not only toenter the field of technical education but also in the world of work.NCERT, for the first time, has developed a textbook on ‘InformativePractices’ to develop skill sets in students to make use of theopportunities provided by ICT.This book focuses on the fundamental concepts related tohandling of data while opening a window to the emerging areas ofdata processing. It seeks to address the dual challenges of reducingcurricular load as well as introducing the latest development in thefield of ICT.As an organisation committed to systemic reforms and continuousimprovement in the quality of its curricular material, NCERTwelcomes comments and suggestions to enable us to bring aboutnecessary changes in its further publications.New DelhiJuly 2019Hrushikesh SenapatyDirectorNational Council of EducationalResearch and Training2020-21Prelims.indd 309-Aug-19 2:28:21 PM

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PrefaceIn the present education system of our country, specialised/disciplinebased courses are introduced at the higher secondary stage. This stageis crucial as well as challenging because of the transition from generalto discipline-based curriculum. The syllabus at this stage needs to havesufficient rigour and depth while remaining mindful of the comprehensionlevel of the learners. Further, the textbook should not be heavily loadedwith content.We are living in an era where information drives many of oursocio-economic decisions. Millions of people are accessing internet roundthe clock for availing various services and thereby generating vast amountof data. Processing of data is becoming a key skill with applicationsacross the disciplines. Thus, study of basic concepts of data handlingand analysis is becoming more and more desirable. There are coursesoffered in the name of computer science, Information and CommunicationTechnology (ICT), Information Technology (IT), etc. by various boards andschools up to the secondary stage, as an optional subject. These mainlyfocus on using computer for word processing, presentation tools andapplication software.Informatics Practices (IP) at the higher secondary stage of schooleducation is also offered as an optional subject. At this stage, studentscan take up IP with the aim of pursuing a career in data science or relatedareas after going through professional courses at higher levels. Therefore,at the higher secondary stage, the curriculum of IP introduces the basicsof database management systems and data processing. The book has eightchapters covering the following broader themes: Basic understanding of computer systems and their evolution,introduction to software and their categorisation, computermemory, awareness of emerging trends in the field of informationand communication technology. Basic constructs of a program using Python programminglanguage — program structure, identifiers, variables, flow of control,advanced data types like Lists and Dictionaries. Handling data using specialised Python library called NumPy — conceptof single and multi-dimensional Array. Concepts of data, database, and relational database managementsystem using MySQL. Structured query language — data definition,data manipulation and data querying.Python programming language and NumPy are introduced using boththe interactive and script mode. A number of hands-on examples are givenin Python, NumPy and MySQL to gradually explain the methodology tosolve different types of problems and handle data. The programming anddatabase related examples as well as the exercises in those chapters arerequired to be solved in a computer and verified with the given outputs.2020-21Prelims.indd 509-Aug-19 2:28:21 PM

viThe chapters in this book have two additional components — activitiesfor self assessment and ‘think and reflect’ to generate further interest inthe learner.Group projects through case studies are proposed to solve complexproblems. Some exercises have been made in case-study form to promoteproblem-finding and problem-solving skills.These chapters have been written by involving practicing teachers aswell as subject experts. These have been iteratively peer-reviewed. Severaliterations have resulted into this book. Thanks to the authors and reviewersfor their valuable contribution.Comments and suggestions are welcome to make this endeavour parexcellence. Dr. Rejaul Karim BarbhuiyaAssistant Professor,Department of Education inScience and Mathematics, NCERT2020-21Prelims.indd 609-Aug-19 2:28:21 PM

Textbook Development CommitteeMembersAnuradha Khattar, Assistant Professor, Miranda House, University ofDelhi, DelhiChetna Khanna, Freelance Educationist, DelhiGurpreet Kaur, PGT (Computer Science), GD Goenka Public School, DelhiHarita Ahuja, Assistant Professor, Acharya Narendra Dev College,University of Delhi, DelhiMudasir Wani, Assistant Professor, Govt. Degree College for Women,Srinagar, Jammu and KashmirOm Vikas, Professor (Retd.), Formerly Director, ABV-IIITM, Gwalior,Madhya PradeshPriti Rai Jain, Assistant Professor, Miranda House, University of Delhi,DelhiRinku Kumari, PGT (Computer Science), Kendriya Vidyalaya, Sainik Vihar,DelhiSharanjit Kaur, Associate Professor, Acharya Narendra Dev College,University of Delhi, DelhiTapasi Ray, Formerly Global IT Director, Huntsman Corporation, SingaporeMember-CoordinatorRejaul Karim Barbhuiya, Assistant Professor, DESM, NCERT, Delhi2020-21Prelims.indd 709-Aug-19 2:28:21 PM

AcknowledgementsThe National Council of Educational Research and Training acknowledgesthe valuable contributions of the individuals and organisation involved inthe development of Informatics Practices textbook for Class XI.The council expresses its gratitude to the syllabus development teamincluding MPS Bhatia, Professor, Netaji Subhas Institute of Technology,Delhi; T V Vijay Kumar, Professor, School of Computer and SystemsSciences, Jawaharlal Nehru University, New Delhi; Zahid Raza, AssociateProfessor, School of Computer and Systems Sciences, Jawaharlal NehruUniversity, New Delhi; Vipul Shah, Principal Scientist, Tata ConsultancyServices, and the CSpathshala team; Smruti Ranjan Sarangi, AssociateProfessor, Department of Computer Science and Engineering, IndianInstitute of Technology Delhi; Vikram Goyal, Associate Professor,Indraprastha Institute of Information Technology (IIIT) Delhi; VandanaTyagi, PGT (Computer Science), Kendriya Vidyalaya, JNU, Delhi and MamurAli, Assistant Professor, Central Institute of Educational Technology,NCERT, New Delhi.The council is thankful to the following resource persons for theircontribution in editing, reviewing, and refining the manuscript of this book:D.N. Sansanwal, Retd. Professor, Devi Ahilya Vishwavidyalaya, Indore;Veer Saini Dixit, Assistant Professor, Atma Ram Sanatan Dharma College,University of Delhi, Delhi; Mukesh Kumar, Teacher, DPS RK Puram, Delhi;Gautam Sarkar, Teacher, Modern School, Barakhamba Road, Delhi; AswinK. Dash, Teacher, Mother’s International School, Delhi; Nancy Sehgal,Teacher, Mata Jai Kaur Public School, Delhi; Neelima Gupta, Professor,Department of Computer Science, University of Delhi; Anamika Gupta,Assistant Professor, Shaheed Sukhdev College of Business Studies,University of Delhi. The council further acknowledges the contribution ofAnuja Krishn, freelance editor, for refining the chapters from languagepoint of view.The council in greatful to Dinesh Kumar, Professor and Head, DESMfor his valuable cooperation and support throughout the developmentof this book.The council also gratefully acknowledges the contributions of MeetuSharma, Graphic Designer; Kanika Walecha, DTP Operator; Pooja, JuniorProject Fellow; Hari Darshan Lodhi and Junaid Ahmed, DTP Operator(Contractual); Chanchal Chauhan, Proofreader (Contractual) andAishwarya Bhattacharyya, Assistant Editor (Contractual), in shapingthis book. The contributions of the office of the APC, DESM andPublication Division, NCERT, New Delhi, in bringing out this book arealso duly acknowledged.2020-21Prelims.indd 809-Aug-19 2:28:21 PM

ContentsForewordiiiPrefaceivChapter 1 Computer System11.11.21.31.4Introduction to Computer SystemEvolution of ComputerComputer MemorySoftwareChapter 2 Emerging tion to PythonPython KeywordsIdentifiersVariablesData TypesOperatorsExpressionsInput and OutputDebuggingFunctionsif.else Statementsfor LoopNested Loops31343434353841424344464850Chapter 4 Working4.14.24.34.415Introduction to Emerging TrendsArtificial Intelligence (AI)Big DataInternet of Things (IoT)Cloud ComputingGrid ComputingBlockchainsChapter 3 Brief Overview1359withofListsandDictionariesIntroduction to ListList OperationsTraversing a ListList Methods and Built-in Functions55555759602020-21Prelims.indd 909-Aug-19 2:28:22 PM