A for loop runs a block of code once for each item in a collection. It’s the most common loop in Python — and almost always the one you want.

Basic for loop

fruits: list[str] = ["apple", "banana", "cherry"]

for fruit in fruits:
    print(fruit)

apple
banana
cherry

Read it as: “for each fruit in fruits, print it”. The variable fruit is a fresh name created by the loop — it takes on each value in turn.

Looping over a string

A string is a sequence of characters, and for loops can walk through it character by character:

for letter in "Python":
    print(letter)

P
y
t
h
o
n

Looping a fixed number of times — range()

To repeat an action a specific number of times, use range():

for i in range(5):
    print(i)

0
1
2
3
4

range(5) produces the numbers 0, 1, 2, 3, 4 — five values, starting at 0 (not 1!).

You can also give range a start and end:

for i in range(2, 6):
    print(i)

2
3
4
5

The end is exclusive — range(2, 6) stops before 6.

And a step:

for i in range(0, 10, 2):
    print(i)

0
2
4
6
8

Negative steps count down:

for i in range(10, 0, -1):
    print(i)

10
9
8
...
1

Looping with an index — enumerate()

If you need both the position and the value, use enumerate():

fruits: list[str] = ["apple", "banana", "cherry"]

for index, fruit in enumerate(fruits):
    print(f"{index}: {fruit}")

0: apple
1: banana
2: cherry

You’ll meet enumerate again in Section 7. It’s the right tool whenever you’d otherwise write for i in range(len(items)): — which is considered un-Pythonic.

Looping over a dictionary

Looping a dictionary visits its keys by default:

prices: dict[str, float] = {"apple": 0.5, "banana": 0.3, "cherry": 1.2}

for fruit in prices:
    print(fruit)

apple
banana
cherry

To get key and value together, use .items():

for fruit, price in prices.items():
    print(f"{fruit}: {price}")

apple: 0.5
banana: 0.3
cherry: 1.2

We’ll cover dictionaries thoroughly in Section 6.

Accumulating values

A very common pattern — build up a result inside a loop:

numbers: list[int] = [10, 20, 30, 40]
total: int = 0

for n in numbers:
    total += n

print(total)   # 100

Python has a built-in sum() for this exact case — but the loop is worth knowing because it’s the general shape: start with an empty result, add to it on each iteration.

A complete example

Counting how many of the numbers from 1 to 50 are even:

count: int = 0

for n in range(1, 51):
    if n % 2 == 0:
        count += 1

print(f"There are {count} even numbers between 1 and 50.")

There are 25 even numbers between 1 and 50.

What’s next

for loops handle the case where you know what to iterate over. Next: while loops, for when you only know when to stop.