Getting Started with Python

What is a programing language?

An ordered set of instructions to be executed by a computer to carry out a specific task is a program. Computers understand the language of 0s and 1s (machine language), but it is difficult for humans to write instructions in 0s and 1s. So we use high programming languages like 𝐏𝐲𝐭𝐡𝐨𝐧.

Features of python

• Open-source language.

• Easy to understand ( clearly defined syntax)

• Case sensitive.

Working with python

we need a python interpreter (online or installed in the system).

• online:-

• Or we can use:-python(3.11.1), visual studio codes, Jupiter notebook etc

  Using an online compiler

  (A)Interactive mode

• We simply type a Python statement.

• We press enter, the interpreter executes the statement.

  

  (B) script mode

In script mode we write a python program in a file, save it and then execute it .

(the saving part may differ in the different interpreters)

Python Keywords

• Reserved words.

• Used only for the purpose for which it has been defined.

• As python is case-sensitive keywords must be written exactly as given below

  

Identifiers

Used to identify a variable

Rules

• The name begins with ( A-Z, a-z, _ ) only.

• It may contain (A-Z, a-z, _ , 0-9) of any length.

• (space, special characters, keywords) are invalid

Variables

• A variable in a program is uniquely identified by a name (identifier)

• Variable in Python refers to an object(value)

  

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Comments

• Not a part of the program.

• Used for easy understanding.

  

Data types

• Every value belongs to a specific data type in python.

• Identifies the type of value a variable can hold.

• **note:-**only list and string are mutable datatype rest are immutable.

  

Functions

• A named group of instructions that can accomplish a specific task.

• can be pre-defined (in the python in the interpreter) OR can be user-defined.

• can be called any number of times.

  

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Basic functions we need to know

• int() [for integers]

• float() [for floating point numbers]

• <variable> =[ ] [to create a list]

• <variable> ='' '' [to create a string]

• <variable> =() [to create a tupule]

• <variable>={ '' '' : '' " or any number , " " : " " -||- .....} [to create a dictionary]

type() [Function]

• If we want to know the type (datatype) of value given to a variable or any other condition we use the type() function.

  

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Operators

• Used to perform a logical operation on values

• the values on which operators work on are called operands

  There are many types of operators

  • Arithmetic operators (+,-,*,/,//,**)

  • Assignment operators (=,+=,-=,*=,/=,%=,//=,**=)

  • Logical operators (and,or,not)

  • Identity operators (is,is not)

  • Membership operators (in , in not)

    click here for more information on operators

## Precedence of operators

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1673726368220/7dede3bd-b2d8-4d39-8cf5-224f5a04ee31.jpeg align="center")

input() [Function]

• The function prompts the user to enter data.

  

output

A Basic python program

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Comment for doubt's 🤖

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