For else in Python

The else statement can also be used with loops, such as for and while loops, to execute a block of code after the loop has completed its iterations without any break statements being encountered.

for i in range(5):
    print(i)
else:
    print("Loop completed without encountering a break statement")

In this case, the else block will be executed only if the loop completes all its iterations without any early termination using the break statement.

Note: the else block is optional, and you can use it according to your specific programming needs.

Python for else example

Here are a few more examples of how the else statement is used in Python:

Checking Prime Numbers

num = 17

if num > 1:
    for i in range(2, num):
        if num % i == 0:
            print(num, "is not a prime number")
            break
    else:
        print(num, "is a prime number")
else:
    print(num, "is not a prime number")

In this example, we’re checking if a given num is a prime number. The else block is used with the for loop to print whether the number is prime or not after completing all iterations.

Handling User Input

username = input("Enter your username: ")

if username == "admin":
    print("Welcome, admin!")
else:
    print("Welcome,", username)

This program asks the user for their username and uses the else block to provide a customized welcome message based on the input.

Finding Factors

num = 28
factors = []

for i in range(1, num + 1):
    if num % i == 0:
        factors.append(i)

print("Factors of", num, "are:", factors)

Here, the else block is not used, but this example shows how you might find factors of a number and create a list of those factors.

Using else with a while Loop

count = 0

while count < 5:
    print("Count:", count)
    count += 1
else:
    print("Loop completed")

Output:

In this example, the else block is executed when the while loop completes all iterations without any break statement.

These examples should help you understand how the else statement is used in various contexts in Python to handle different scenarios.

Note: IDE: PyCharm 2021.3.3 (Community Edition)

Windows 10

Python 3.10.1

All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.