Python For All: Input and Output Statements

#Example progrm for input and output statement
eno=int(input("enter emp no "))
ename=input("enter employee name ")
esal=float(input("enter emp sal "))
eaddr=input("enter emp address ")
marital=bool(input("employee married?: True/False "))
#displaying the emp data
print("empno=",eno)
print("emp name=",ename)
print("emp salary=",esal)
print("emp address=",eaddr)
print("emp marrie ?",marital)

"""output:
enter emp no 007
enter employee name Rajesh
enter emp sal 35000
enter emp address Kurnul
employee married?: True/False True

input()

It is a predefined method. The input() reads a line from input, converts into a string and returns it.

#Example program

a=int(input("enter 1 value"))

b=int(input("enter 2nd value"))

print(a,b)

print("product =",a*b)

Output:

enter 2 numbers:10 20

10 20

product = 200

If I dont write type cast into int? i.e a=int(input("enter value"))

Error: can't multiply sequence by non-int of type 'str'

i.e print("product =",a*b)

#how to read multiple values from the keyboard in a single line

a,b=(int(x) for x in input("enter 2 numbers:").split())

print(a,b)

print("product =",a*b)

"""output:

enter 2 numbers:10 20

10 20

product = 200

1Q: Why do use split()?

Ans: There are two reasons:

(1) It leads to error if I give i/ps by giving spaces.

Ex: 10 20 #error

(2) It takes only 1 input, and stores into two inputs like 1 and 0

so we will get a result like the below:

1 0

product=0

so the split() function is mandatory when we want to read more than one i/p from the keyboard

What is split()?

The split() method splits a string into a list.

You can specify the separator, the default separator is any whitespace.

Example:

"2 4".split() #We have to call the split() function w.r.t string

['2', '4']

>>> "1, 2 3 Hyd, Vij Kurnul,Kadapa atp".split(',')

['1', ' 2 3 Hyd', ' Vij Kurnul', 'Kadapa atp']

>>>

print(“Hello how are you”)

The print() prints the specified message to the screen. The message can be a string, object, any other type variable.

Ex 1: print() without any argument just it prints new line character

Ex 2:
print("hello ")
print("Hi\nhow are you")
output:
Hi
how are you
print("Hi\thow are you")
Hi how are you

Ex3: Find ncr and npr:
"""
c= no of distinct combinations
n=total no of objects in the set
r=no of choosing objects from the set
5c2=n!/(n-r)!
Input: Two positive integers as the total no of objects and sample size
Output:A positive integer as the permutation or permutation of 'n' objects
taken at 'r' at a time
"""
import math
#n,r=(int(x)for x in input("enter 2 numbers:").split())
n=int(input("enter n value: ="))
r=int(input("enter r value: ="))
if n>=r:
print("ncr=",math.factorial(n)/(math.factorial(r)*math.factorial(n-r)))
print("npr=",math.factorial(n)/(math.factorial(n-r)))
else:
print("value of n can not be <r")

"""enter n value: =5
enter r value: =2
ncr= 10.0
npr= 20.0
>>>
===================== RESTART: F:\Programs\input\ncr.py =====================
enter n value: =2
enter r value: =5
value of n can not be <r
>>> """

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