If Else in Python

In every language we need some keywords for decision-making. In Python, we have mainly three keywords for decision-making. These are:
  1. if
  2. elif
  3. else

If in Python

In Python when we need to execute a block of code based on some condition then we use 'if' keyword. Code defined inside 'if' block will execute only if the condition given in parenthesis of 'if' is true.
Syntax:
if(condition_1):
    this block will execute only if condition_1 is true
Example:

age = 20

if age>18:
    # in python spaces are very important
    # Python uses these spaces to identify blocks of codes
    # way of giving spaces at beginning of lines is called indentation 
    print("You can Vote")
    
Output:
    You can Vote

Elif in Python

It is used when we have multiple conditions and we need to run different codes on different conditions. It is same as 'else if' of C++ or Java.
Syntax:
if (condition_1):
    this block will execute only if condition_1 is true
elif (condition_2):
    this block will execute only if condition_2 is true
elif (condition_3):
    this block will execute only if condition_3 is true
Example:

num1 = 12
num2 = 10

op = "+"

if (op == "+"):
    print(num1 + num2)
elif (op == "-"):
    print(num1 - num2)
elif (op == "*"):
    print(num1 * num2)
    
Output:
    22

Else in Python

It is used to run a piece of code when all conditions specified in 'if' or 'elif' are false.
Syntax:
if (condition_1):
    this block will execute only if condition_1 is true
elif (condition_2):
    this block will execute only if condition_2 is true
elif (condition_3):
    this block will execute only if condition_3 is true
else:
    this block will execute when condition_1, condition_2 and condition_3 are false
Example:

num1 = 12
num2 = 10

op = "/"

if (op == "+"):
    print(num1 + num2)
elif (op == "-"):
    print(num1 - num2)
elif (op == "*"):
    print(num1 * num2)
else:
    print("Your operator is not valid")
    
Output:
    Your operator is not valid