Python user Input and Print function

 

Input and Print function in Python

input() :

• this function is used to collect input from user at run time

 #program to run time data from user
 name = input("Enter name: ")

 #output
 Enter name:

• lets provide input

Enter name: Techno Xpresss

print() :

• this function is used to print data on console/output window

 #program to print data on console
 print("Hey let's learn Python")

 #output
 Hey let's learn Python

Example :

 #program to take user input and print on console

 name = input("Enter name: ")
 print("Hey", name, "let's learn Python")


 #output
 Enter name: Techno Xpresss
 Hey Techno Xpresss let's learn Python

But input() has its own limitation while collecting input at run time, let's have a look at the below example

 #program to take input from user and perform certain action  

 a = input("enter num1 : ")
 b = input("enter num2 : ")
 c = a + b

 print ("a:", a)
 print ("b:", b)
 print ("c:", c)

our expectation from above example, 

• at run time, it will ask user to provide 2 numbers which we are storing in a and b.
• suppose user entered a as 5 and b as 10
• then printing a, b and c(sum of a and b)
• expected output is
• a is 5
• bis 10
• c is 15

 #output
 enter a: 5
 enter b: 10
 a: 5
 b: 10
 c: 510

a and b are as expected but not c.

Limitation of input()

Example:

 #program to take input from user and perform certain action

 name=input("Enter name : ")
 age =input("Enter age in years : ")
 marks = input("Enter % scored :")
 print ("Hey",name,"you are",age,"years old and you scored",marks, "% marks")


 #output
 Enter name : Techno Xpresss
 Enter age in years : 28
 Enter % scored :80.72
 Hey Techno Xpresss you are 28 years old and you scored 80.72 % marks

so above example is needed to enter few values from user and expectation is

• name   : string
• age      : integer
• marks  : float

Hey Techno Xpresss you are 28 years old and you scored 80.72 % marks

this above message from output looks meaningful

lets see what type of data is assigned to name , age and marks

 #program to take input from user to understand type of data input function returns

 name=input("Enter name : ")
 age =input("Enter age in years : ")
 marks = input("Enter % scored :")
 print ("Hey",name,"you are",age,"years old and you scored",marks, "% marks")
 print("typeof(name)",type(name), "\ntypeof(age)",type(age), "\ntypeof(marks)",type(marks))

 #output
 Enter name : Techno Xpress
 Enter age in years : 28
 Enter % scored :80.72
 Hey Techno Xpress you are 28 years old and you scored 80.72 % marks

 typeof(name) <class 'str'>
 typeof(age) <class 'str'>
 typeof(marks) <class 'str'>

It is clearly visible that input returns the data as a 'str class' object. 

This is the reason that when we tried to add 5 and 10 above, instead of 15 we got 510 (as a and b were collected as string and when we add then, b got cascaded to a)

input() always return used provided data as a string.

So to collect data as integer or float, we have to do typecasting