Python Loops Made Easy: A Practical Guide to For and While Loops

What are Loops?

Loops are one of the most important concepts in python. Loops allows us to write the same block of code multiple times without rewriting it again and again. There are 2 types of loops in python for loop and While loop. Mastering loops will make your code efficient, readable and powerful.

Why we need Loops?

Take an example you want to print numbers from 1 to 100. Writing print() command for 100 times is impractical and time consuming. Here loops allows us to do the same task in few lines of code.

The for loop:

for loop in python is use to iterate over a sequence (list, tuple, string, range).

Example 1:

for i in range(1, 6):
    print(i)

output: 1 2 3 4 5

Example 2:

fruits = ["apple", "banana", "mango"]
for fruit in fruits:
    print("I like", fruit, sep=",")

output: I like apple, I like banana, I like mango

When to use for loop: When you know the number of iterations means you already know how many times you need to run the program or you want to go through the elements of collections.

The While loop:

The while loop will be in action until the condition is true.

Example 1: Counting till 5

count = 1 # initialized count as 1
while count <= 5: # set the condition while count is less than or equal to 5
    print(count) # Print the values of count
    count += 1 # Count will increment until it is equal to 5

Output: 1 2 3 4 5

Example 2: User controlled Loop

password = "" # Initialized password as an empty string
while password != "python123": # Set the condition that the value of password should be "python123"
    password = input("Enter password: ") # while the above password is entered system keeps asking for the password
print("Access granted!") # Once the correct password is entered this message will appear.

When to use While Loop: When you don’t know the number of iterations means you don’t know how many times the loop should run and the stopping point depends on the condition given to while loop.\

Loop control statement

Sometimes you need extra control inside loops. Python provides special keywords for this:

• break → exit the loop completely

• continue → skip the current iteration and move to the next

• else with loops → runs only if the loop ends normally (not by break)

Example: Using break and continue

pythonfor num in range(1, 10):
    if num == 5:
        break   # stop the loop when num is 5
    if num % 2 == 0:
        continue   # skip even numbers
    print(num)

Practical use case of loops

• Data processing: Iterating through a dataset row by row

• User input validation: Keep asking until correct input is given

• Automation: Sending bulk emails or messages

• Algorithm implementation: Searching, sorting, and traversing data structures