welcome to the python

hello there are some  exercises that might be helpful for you to learn python in easy way.

•  print('mohsin') or print("mohsin")      to print mohsin on screen .

 here you can write anyting in the cotations to display anything on the screen.

you can also use print to call any previous  defined or initialized value like

                                price = 10

                  print(price)

this is the code that is going to display value 

of price on the screen.

it means when you use print without quoations

 like print(price) it will

 display the value of the variable that you 

entered in the small brackets.

   so it means that print can either 

display value and it can call the 

variables also .

so

it can involve 2 functions in its brackets

examle

          if we write this code 

     print(' *  ' *10)

           then we will see ********** on screen 

which means that the print can   executes 

multiply the 

add subtract and other mathematical in its brackets.

structure of pythen (how compiler works )


pythen compiler runs line by line from the top .

example 

if you  initialize the value of price 10 

and then again initialize 

the same variable then it will 

act like updated . 

your code will be like.  

price=10

price=20

     print (price)

then output will be displayed

 20 not 10 . because python runs 

the program line by line from the top.

Taking input 


we use   the label input to take an input from the user 

example 

if you want user to tell his name then yo can write 

input('what is your name ') 

what is your name will be make a space on screen for the user 

to enter his/her name in the empty space.

   if   

you want to give an auto reply

 service you can use  these two tools to make the code

    example

name = input('what is your name ')

print ('hi' + name)

if 

 you want to ask some questions from user 

and the requirement is we have to sum his answer

for example

  ask a question what is your name then 

ask another

 question what is your age then 

ask another question what is your favourite color

your code will be like 

name = input('what is your name    '  )

age=  input('what is your age ')

color =input('what is your favourite color')

print(name   +'likes  '   + color   +   age)



Data type


you can also set the specific data type like 

int()   for non point numbers

float() for point numbers 

str() for the characters

for example 

you are asking your user to enter 

his date of birth and you want 

only  numbers and you want to calculate

 his current age 

then you can write the code like this 



birth_year =input("birth year")
age= 2020 - int(birth_year)
print(age)




if you have a situation where you have to convert weight from lbs to kg then
your code will be like 


weight =input("enter your weight :lbs")
waight = int(weight) * 0.45print(waight)




if you want to print first word or any of word that user input then your code would be like 


name=input("what is your name ")
print(name[0]) 


if you want to print second word or any of word that user input then your code would be like 


name=input("what is your name ")
print(name[1])


if you want to print secondlast word  that user input then your code would be like 


name=input("what is your name ")
print(name[-2])  


and so on


if you want to print first 3 word  that user input then your code would be like 


name=input("what is your name ")
print(name[0:3])
 
if you want to print last 3 word  that user input then your code would be like 


name=input("what is your name ")
print(name[2:5])


if you wrote  : then it will devide the number if you write 1:5 then it will skip the  value of index 
which is written in index 0


 
if you want to print with skipping the first and the last  word  that user input then your code would be like 


name=input("what is your name ")
print(name[1:-1])