Python If Else Elif

If the condition is true its body will execute otherwise does not execute.

It is used to test the condition and the result is based on the condition.

Syntax

``````if  condition  :
body ``````

Example

``````num = int(input("Enter a Number "))
if num > 0:
print("Number is greater than 0")
``````

Output

``````Enter a Number 1
Number is greater than 0
``````

Same as we can use the following comparison operators to compare two values

comparison operators
Operator Meaning Example
`==` Equals `if x == y`
`!=` Not equals `if x != y`
`>` Greater than `if x > y`
`>=` Greater than or equal to `if x >= y`
`<` Less than `if x < y`
`<=` Less than or equal to `if x <= y`

Example 2:  Check given number is positive or negative or zero Using if Condition

``````num = int(input("Enter a Number "))
if num > 0:
print("Number is greater than 0")
if num < 0:
print("Number is less than 0")
if num == 0:
print("Number is 0")
``````

Output

``````Enter a Number -1
Number is less than 0``````

Indentation

Python depends on indentation (whitespace at the beginning of a line) to determine the scope of the code. Other programming languages usually use curly brackets for this purpose.

Example

``````num = int(input("Enter a Number "))
if num > 0:
print("Number is greater than 0")
``````

Output

``IndentationError: expected an indented block``

If else statement

If the condition is the true body of if will execute otherwise body of else execute.

Example

``````num = int(input("Enter a Number "))
if num >= 0:
print("Number is greater than 0 or 0")
else:
print("Number is less than 0")
``````

Output

``````Enter a Number -1
Number is less than 0
``````

Check given number is even or odd

``````num = int(input("Enter a Number "))
if num % 2 == 0:
print("Number is Even")
else:
print("Number is Odd")
``````

Output

``````Enter a Number 2
Number is Even``````

It is used to test the condition.

If executes only one condition at a time.

The condition which is true first from the top will execute.

Syntax

``````if  condition  :
body1
elif condition:
body2
elif condition:
body3
else:
body4``````

Example 1

``````num = int(input("Enter a Number "))
if num > 11:
print("body 1")
elif num > 5:
print("body 2")
elif num > 1:
print("body 3")
else:
print("body 4")
``````

Output

``````Enter a Number 2
body 3``````

else part will execute if all the conditions are false.

Example 2

``````num = int(input("Enter a Number "))
if num > 11:
print("body 1")
elif num > 5:
print("body 2")
elif num > 1:
print("body 3")
else:
print("body 4")
``````

Output

``````Enter a Number -1
body 4
``````

Example 3

``````marks = int(input("Enter your Marks "))
if marks > 85 and marks <= 100:
print("Congrats ! you scored grade A")
elif marks > 60 and marks <= 85:
``````Enter your Marks 54