Getting started with Python
Python Introduction
Python Data Types
Python String Methods
Python Lists, Tuples and Sets
Python Dictionary
Python Conditional Statements and Loops
Python Functions
Python OOPs
Python Classes, Objects and Constructor
Python Inheritance
Python Iterators
Python Scopes
Python Module
Python Try Except
Python File Handling

Getting started with Python

Running our First Python Program

Open any text editor and save the file as demo.py and write the following code.

print("Hello World !")

To run the program from CMD open command prompt and go to the file directory and run the following command

python hello.py

OUTPUT:

Hello World !

NOTE: You just need to click on run button to run the program if you are using visual studio or any similar type of editor.

Comments in Python

For single line comment, we just need to write # at the start of the line.

For multi-line comment, the comments are written in between three double quotes like this
" " "
Multi-
Line
Comment
" " ".

Note : In Python we don't use braces instead we use Identation ( which is also mandatory ) like below

if n > 2:
    print("The number is greater than 2")
elif n < 2 :
    print("The number is less than 2")
else :
    print("The number is 2")
    
#skipping the Identation will raise error

Python Variables

In python, declaring a variable is very simple.

#Integer
n = 45

#Floating Point Number
n = 45.456

#String
n = "Hello Everyone"

GLOBAL VARIABLE : These variables are created outside of a function.

LOCAL VARIABLE : These variables are created inside a function.

GLOBAL KEYWORD : To create a global variable inside a function global keyword is used.

def fun():
global x

To change the value of global variable which is outside of that function we use global keyword to do that.

x = "Hello"
def test():
    global x
    x="wellcome"
    print(x)