Computer Science Class - 12 Notes

Python

Python is a high-level, interpreted programming language known for its simple, readable syntax and broad versatility. It supports multiple programming paradigms, including procedural, object-oriented, and functional programming. Python is widely used in web development, data analysis, artificial intelligence, automation, and software development due to its large standard library and a vast ecosystem of third-party packages.

Keywords & Identifiers

Keywords are reserved words. Each keyword has a specific meaning to the python interpreter, and we can use a keyword in our program only for the purpose for which it has been defined.

Identifier : In programing languages, identifiers are names used to identify a variable, function or other entities in a program.

Common Keywords : True, def, and, del.

Variables

Container for storing data. It allocates memory to store data values.

x = 5
name = "dan"

Operators in Python

Arithmetic Operator
Comparison Operator
Logical Operator
Assigment Operator
Identity Operator
Membership Operator

Flow Control

Selection - Conditional ( if, elif, else )
Repetition - loops ( for, while )

for loops are used to traverse through a sequence.

Data Structures

String

Sequence of characters.
Created using a single quote, double quote, triple quotes.

Characters in string can be accessed using indexes.

String Operations

Concatenation
Repetition
Membership
Slicing

String Functions

len
title
count
split
partition

List

sequence data type
store multiple values
can store different data types.

Tuple

sequence data type
store multiple values
can store different data types.
Tuple is immutable

Dictionary

Items are stored as key value pairs.
keys are unique.

Functions

Code block that is executed on call. Functions can take in positional and keyword arguments.