Python: Input and Output

Input and Output

1. How to Input the Data through Keyboard?

In python it is possible to input the data using a keyboard.

For that purpose, the function input() is used.

Syntax

input([prompt])

Where prompt is the string we wish to display on the screen. It is optional.

In the following screenshot, the input method is used to get the data.

In [2]: a = input("Enter some number: ")

Enter some number: 10

In [3]: a

Out [3]: '10'

Enter the hot key Shift+Enter key to get the output.

Example: 1

Write a python program to perform addition of two numbers. Accept the two numbers using the keyboard.

Solution:

In [4]: print("Enter first number")

a = int(input())

Enter first number

10

In [5]: print("Enter second number")

b = int(input())

Enter second number

20

In [6]: c = a+b

print("The addition of two numbers is: ",c)

The addition of two numbers is: 30

Program explanation:

•  In above program, we have used input() function to get the input through keyboard. But this input will be accepted in the form of string.

•  For performing addition of two numbers we need numerical values and not the strings. Hence we use int() function to which the input() function is passed as parameter. Due to which whatever we accept through keyboard will be converted to integer.

• Finally the addition of two numbers as a result will be displayed.

Example:2

Write a python program to find the square root of a given number.

Solution:

print("Enter the number:")

num=float(input())

result=num**0.5

print("The square root of ",num," is ",result)

Example:3

Write a program in python to obtain principle amount, rate of interest and time from user and compute simple interest.

Solution :

Create a python file using Jupyter Notebook as follows

Save the above file as Interest.py

Output

In [1]: import Interest

Enter principal amount:

1000

Enter rate of interest:

6.5

Enter number of years:

5

Simple Interest is: 325.0

2. How to Display Output on Console using Format?

Using .format the data can be displayed on the console. For that purpose { } and .format is used. For example

Example 1 :

n=10

print("There are {} numbers".format(n))

Output

There are 10 numbers

We can also display the data along with some space. For that purpose, we have to use {:n}.

For example ‒

Example 2:

n=10

print("There are {:10d} numbers".format(n))

Output

There are         10 numbers

Example:3

a=10

b=20

c=30

print("There are three numbers and those are {} {} {} numbers".format(a,b,c))

Output

There are three numbers and those are 10 20 30 numbers

Example: 4

Write a program to swap two numbers.

Solution:

a= input('Enter value of a:')

b = input('Enter value of b: ')

temp = a

a= b

b = temp

print('After swapping a: {}'.format(a))

print('After swapping b: {}'.format(b))