The document discusses Python's if-else conditional statements. It provides examples of using if-else to check 1) if a user's age is greater than or equal to 18, 2) if a number is positive or negative, 3) if a number is even or odd, 4) if a number is divisible by 3 or 7, and 5) if a year is a leap year. The last example shows how to find the maximum between two numbers using if-else. The syntax and logic of if-else statements are explained through these examples.

1. Python Flow Control
Class: XI
Computer Science-083
If..else conditions
Part-2

2. if .. else Statement
The if ..else.. statement is used to test a specific condition. If the condition is true , a
block of code or block of statements will be executed, otherwise false section statement
will be executed
Syntax:
if condition or expression:
-----Statements-------
-----Statements-------
else:
-----Statements-------
-----Statements-------
This is True
part of if
condition
This is False
part of if
condition

3. Let us understand how the if..else work
F the question is to check the user input age is more than equal to 18 or not, if yes
than display “Valid to Vote” , otherwise display “Not valid to vote”
age=int(input(“Enter the age:”))
if (age>=18):
print(“Valid to vote”)
print(“Valid to vote”)
else:
Enter the age: 20
Valid to vote
If the condition is TRUE
If the condition is False

4. Let us understand how the if..else work
Program to accept number from user and check that number is positive or
negative.
no=int(input(“Enter the no:”))
if (no>0):
print(“It’s a positive value”)
print(“It’s a negative value”)
else:
Enter the no: -9
It’s a negative value

5. Let us understand how the if..else work
Program to accept number from user and check that number is even or
odd.
no=int(input(“Enter the no:”))
if (no%2==0):
print(“It’s a Even number”)
print(“It’s a Odd number”)
else:
Enter the no: 5
It’s a Odd number
Enter the no: 2
It’s a Even number

6. Let us understand how the if..else work
Program to accept number from user and check that number is divisible by
3 or 7 or not
no=int(input(“Enter the no:”))
if (no%3==0 or no%7==0):
print(“Number is divisible by 3 or 7”)
print(“Number is not divisible by 3 or 7”)
else:
Enter the no: 15
Number is divisible by 3 or 7

7. Let us understand how the if..else work
Program to accept year from user and check that year is a leap year or not.
Example : year is leap year if it is divisible by 4 or 400 or 100
yy=int(input(“Enter the year:”))
if (yy%4==0 or yy%400==0 or yy%100!=0):
print(“It’s a leap year”)
print(“Its not a leap year”)
else:
Enter the year:2005
A year is said to be leap year, if the year is exactly divisible by 4 but and not
divisible by 100. Year is also a leap year if it is exactly divisible by 400.

8. Let us understand how the if..else work
Program to accept number and find maximum between two numbers
a=int(input(“Enter the value a:”))
if (a>b):
print(“A greater than B”)
print(“B is greater than A”)
else:
Enter the value a: 5
Enter the value b: 2
A is greater than B
b=int(input(“Enter the value b:”))