Input and Output

Taking Input and showing Output in required way plays an important role in interactive coding. So lets focus on input and output of various data types.

raw_input()

this is used to take input as long as it reached end of line.Note that there should not be any spaces.Taking input terminates with a new line character and if there are any spaces in the input line it results in error

# Prints out the input received from stdin
astring=raw_input()# give hello as input
print raw_input()

after taking the input we can convert them to our required data type using functions like int(),float(),str()

num=int(raw_input())
print num
decimalnum=raw_input()
decimalnum=float(raw_input()
print decimalnum

input()

this is especially used to input integers. The advantage of input() over raw_input() can be cleared with the following example

#give 2*2 as input
a=input()
b=raw_input() #note that int(raw_input()) results in error
print a #prints 4
print b #prints 2*2

how to take two two or more data types as input from a single line separated by spaces?

Here we make use split() and map() functions

#give two integers in first line and more than two integers in third line
a, b = map(int, raw_input().split())
array = raw_input().split()
sum = 0
for each in array:
    sum = sum + int(each)
print(a, b, sum)  # prints first two integers from first line and sum of integers of second line

Output formatting

You might have already noticed that print statement automatically inserts a new line. The use of comma like in the above code prints the values in a single line separated by a space. The sys module provides various functions for output formatting but here we learn how to use basic knowledge of formatting to output in our required way. Lets see a few examples to learn output formatting

a = 5
b = 0.63
c = "hello"
print "a is : %d, b is %0.4f,c is %s" % (a,b,c)

The output must be self explanatory.

Exercise

Write a program that asks the user to input their name, age, and country. The program should then print out a message that includes this information in a sentence. The program should include:

1. Taking a name as input using raw_input().
2. Taking an age as input using input(), and converting it to an integer.
3. Taking a country name as input using raw_input().
4. Formatting the output to display a sentence that includes the name, age, and country.

The program should demonstrate input handling and string formatting in Python.

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