Getting Started with Python

Getting Started with Python

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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 ๐๐ฒ๐ญ๐ก๐จ๐ง.

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.

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A Basic python program

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Comment for doubt's ๐Ÿค–

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