if and elif

The elif statement in Python, short for “else if,” allows you to check multiple conditions in sequence. It provides a way to handle more than just two possible outcomes (as with a simple if and else). With elif, you can check for additional conditions after the initial if statement, and only the first condition that evaluates to True will have its corresponding block of code executed.

Example of elif Usage

Here’s a basic example:

a = 10.0
b = 10.0

if a < b:
    print("a is smaller than b")
elif a == b:
    print("a equals b")
# Output:
# a equals b

In this example, the first if condition a < b is False, so Python checks the elif condition a == b, which is True, so the message “a equals b” is printed.

Multiple elif Statements

You can include multiple elif statements to check for a variety of conditions:

x = 25

if x < 10:
    print("x is less than 10")
elif x < 20:
    print("x is less than 20 but greater than or equal to 10")
elif x < 30:
    print("x is less than 30 but greater than or equal to 20")
# Output:
# x is less than 30 but greater than or equal to 20

In this example, Python evaluates each condition in sequence. Since x is 25, the first two conditions are False, but the third elif condition is True, so the corresponding message is printed.