Loops in Python

Loops allow you to repeat a block of code multiple times. This is essential for tasks like processing items in a list, counting, or keeping a program running until a condition changes.

Which Loop to Use?

The for Loop

The for loop is used to iterate over a sequence (like a list, tuple, string, or range).

Looping through a Range

The range() function generates a sequence of numbers.

Looping through a String

You can loop through each character in a string.

Looping through a List

Looping through a Dictionary

You can iterate over keys, values, or both.

The while Loop

The while loop repeats code as long as a condition is True.

Interactive Example: Sum of Numbers

Let's calculate the sum of numbers from 1 to 10.

Quiz

Key Takeaways

✅ for loops iterate over sequences (lists, strings, ranges)
✅ range(start, stop, step) generates numbers
✅ while loops run as long as a condition is True
✅ Use .items() to loop through dictionary keys and values

What's Next?

In the next lesson, we'll master loop control:

• break to exit loops early
• continue to skip iterations
• else clauses in loops
• Nested loops

Keep coding! 🚀