Class 12 Computer Science Notes – Code 083

Class 12 Computer Science Notes

Unit I: Computational Thinking and Programming – 2 – Notes

  • Revision of Python topics covered in Class XI.
  • Functions: types of function (built-in functions, functions defined in module, user defined functions), creating user defined function, arguments and parameters, default parameters, positional parameters, function returning value(s), flow of execution, scope of a variable (global scope, local scope)
  • Exception Handling: Introduction, handling exceptions using try-except-finally blocks
  • Introduction to files, types of files (Text file, Binary file, CSV file), relative and absolute paths
  • Text file: opening a text file, text file open modes (r, r+, w, w+, a, a+), closing a text file, opening a file using with clause, writing/appending data to a text file using write() and writelines(), reading from a text file using read(), readline() and readlines(), seek and tell methods, manipulation of data in a text file
  • Binary file: basic operations on a binary file: open using file open modes (rb, rb+, wb, wb+, ab, ab+), close a binary file, import pickle module, dump() and load() method, read, write/create, search, append and update operations in a binary file
  • CSV file: import csv module, open / close csv file, write into a csv file using writer(), writerow(), writerows() and read from a csv file using reader()
  • Data Structure: Stack, operations on stack (push & pop), implementation of stack using list.

Unit II: Computer Networks – Notes

  • Evolution of networking: introduction to computer networks, evolution of networking (ARPANET, NSFNET, INTERNET)
  • Data communication terminologies: concept of communication, components of data communication (sender,receiver, message, communication media, protocols), measuring capacity of communication media (bandwidth, data transfer rate), IP address, switching techniques (Circuit switching, Packet switching)
  • Transmission media: Wired communication media (Twisted pair cable, Co-axial cable, Fiber-optic cable), Wireless media (Radio waves, Micro waves, Infrared waves)
  • Network devices (Modem, Ethernet card, RJ45, Repeater, Hub, Switch, Router, Gateway, WIFI card)
  • Network topologies and Network types: types of networks (PAN, LAN, MAN, WAN), networking topologies (Bus, Star, Tree)
  • Network protocol: HTTP, FTP, PPP, SMTP, TCP/IP, POP3, HTTPS, TELNET, VoIP
  • Introduction to web services: WWW, Hyper Text Markup Language (HTML),
  • Extensible Markup Language (XML), domain names, URL, website, web browser, web servers, web hosting

Unit III: Database Management – Notes

  • Database concepts: introduction to database concepts and its need
  • Relational data model: relation, attribute, tuple, domain, degree, cardinality, keys (candidate key, primary key, alternate key, foreign key)
  • Structured Query Language: introduction, Data Definition Language and Data Manipulation Language, data type (char(n), varchar(n), int, float, date), constraints (not null, unique, primary key), create database, use database, show databases, drop database, show tables, create table, describe table, alter table (add and remove an attribute, add and remove primary key), drop table, insert, delete, select, operators (mathematical, relational and logical), aliasing, distinct clause, where clause, in, between, order by, meaning of null, is null, is not null, like, update command, delete command, aggregate functions (max, min, avg, sum, count), group by, having clause, joins: cartesian product on two tables, equi-join and natural join
  • Interface of python with an SQL database: connecting SQL with Python, performing insert, update, delete queries using cursor, display data by using connect(), cursor(), execute(), commit(), fetchone(), fetchall(), rowcount, creating database connectivity applications, use of %s format specifier or format() to perform queries 

Practical List

Suggested Reading Material

Project

The aim of the class project is to create something that is tangible and useful using Python
file handling/ Python-SQL connectivity. This should be done in groups of two to three
students and should be started by students at least 6 months before the submission
deadline. The aim here is to find a real world problem that is worthwhile to solve.
Students are encouraged to visit local businesses and ask them about the problems that
they are facing. For example, if a business is finding it hard to create invoices for filing GST
claims, then students can do a project that takes the raw data (list of transactions), groups
the transactions by category, accounts for the GST tax rates, and creates invoices in the
appropriate format. Students can be extremely creative here. They can use a wide variety of
Python libraries to create user friendly applications such as games, software for their school,
software for their disabled fellow students, and mobile applications, of course to do some of
these projects, some additional learning is required; this should be encouraged. Students
should know how to teach themselves.
The students should be sensitized to avoid plagiarism and violations of copyright issues while
working on projects. Teachers should take necessary measures for this.