The Else Keyword
The else keyword catches anything which isn't caught by the preceding conditions.
The else statement is executed when the if condition (and any elif conditions) evaluate to False.
Example
a = 200
b = 33
if b > a:
print("b is greater than a")
elif a == b:
print("a and b are equal")
else:
print("a is greater than b")
In this example a is greater than b, so the first condition is not true, also the elif condition is not true, so we go to the else condition and print to screen that "a is greater than b".
Else Without Elif
You can also have an else without the elif:
Example
a = 200
b = 33
if b > a:
print("b is greater than a")
else:
print("b is not greater than a")
This creates a simple two-way choice: if the condition is true, execute one block; otherwise, execute the else block.
How Else Works
The else statement provides a default action when none of the previous conditions are true. Think of it as a "catch-all" for any scenario not covered by your if and elif statements.
Note: The else statement must come last. You cannot have an elif after an else.
Example
number = 7
if number % 2 == 0:
print("The number is even")
else:
print("The number is odd")
Complete If-Elif-Else Chain
You can combine if, elif, and else to create a comprehensive decision-making structure.
Example
temperature = 22
if temperature > 30:
print("It's hot outside!")
elif temperature > 20:
print("It's warm outside")
elif temperature > 10:
print("It's cool outside")
else:
print("It's cold outside!")
Else as Fallback
The else statement acts as a fallback that executes when none of the preceding conditions are true. This makes it useful for error handling, validation, and providing default values.
Example
username = "Emil"
if len(username) > 0:
print(f"Welcome, {username}!")
else:
print("Error: Username cannot be empty")
