Python for Loop: Repeat Code for Each Item

What Is a for Loop?

A for loop runs the same lines of code once for every item in a list. You write the lines once, and Python repeats them for you.

Say you want to greet three friends. Without a loop, you write one print() per friend:

123print("Hello, Sunny!")
print("Hello, Rocky!")
print("Hello, Lucky!")

That works for three friends. But for 300? With a for loop and the list from chapter 9, two lines do it all:

123friends = ["Sunny", "Rocky", "Lucky"]
for friend in friends:
    print("Hello,", friend + "!")

Add a fourth name to the list and run it again. The loop greets everyone, and you didn't touch the print() line.

Think of it like a teacher calling the roll: the teacher goes down the list, one name at a time, and does the same thing for each name.

How it runs

• Python takes the first item from the list and puts it in friend.
• It runs the indented lines.
• Then it takes the next item and runs the lines again.
• When there are no items left, the loop ends and Python carries on below it.

Each run of the indented lines is called an iteration (a fancy word for "one time round").

The "go back up" is what makes it a loop: the same two boxes run again and again, once per name.

A for loop repeats its indented lines once for every item in a list.

Writing a for Loop: Colon and Indentation

A for loop has a fixed shape: the words for and in, a colon, and an indented block. It looks a lot like the if from chapter 8.

12345prices = [20, 35, 50]
for price in prices:
    print("Price:", price)
    print("With tax:", price + 5)
print("All done")

Think of it like a stamp: everything carved into the stamp (the indented lines) gets printed on every page (every item).

The parts

Inside or after the loop

• Every line indented by 4 spaces under the for is inside the loop. It runs once per item.
• The first line that is not indented is after the loop. It runs once, when the loop is finished.

That's why All done appears only once, at the end.

Forget the colon

123names = ["Sunny", "Rocky"]
for name in names
    print(name)

Forget to indent

123names = ["Sunny", "Rocky"]
for name in names:
print(name)

Don't be scared of these errors! They're the same ones you met with if, and Python tells you exactly what's missing.

for item in list: then the block, indented by 4 spaces.

Looping Over a String

A for loop works on strings too. It goes through the string one character at a time: every letter, digit, space and symbol.

123word = "Sunny"
for letter in word:
    print(letter)

Think of it like reading a word out letter by letter, the way you spell your name on the phone.

The rules

• for ch in text: gives you one character per iteration, from left to right.
• Spaces are characters too, so they get their own turn.
• The loop runs len(text) times (chapter 5).

12for ch in "Hi Rocky":
    print(ch, end="-")

See the space between the two dashes? That's the space character getting its turn. end="-" is the trick from chapter 2: it ends each print() with a dash instead of a new line.

Loop over what the user types

This works with input() from chapter 7, so your program can spell any word:

123name = input()
for ch in name:
    print(ch, end=" ")

Type your own name in the Input box and run it again.

Common beginner doubt: "Can I loop over a number, like 12345?" No. A number isn't a sequence of characters, so Python stops with TypeError: 'int' object is not iterable ("iterable" means "something a loop can go through"). Loop over a string or a list instead. You'll see this error again in the last topic.

A for loop over a string gives you one character at a time, spaces included.

The Loop Variable

The variable between for and in is the loop variable. Python gives it a new value at the start of every iteration: the next item.

123456marks = [72, 38, 91]
for mark in marks:
    if mark >= 40:
        print(mark, "pass")
    else:
        print(mark, "fail")

Inside the loop, you can use it like any other variable: print it, do maths with it, or test it with an if from chapter 8. The if block is indented 8 spaces: 4 for the loop, 4 more for the if.

Think of it like a name badge passed down a line of people: whoever is wearing the badge right now is the current item.

Choose a good name

• Name the list in plural and the loop variable in singular: for mark in marks:, for name in names:.
• For characters, ch or letter is common: for ch in word:.
• Any valid variable name works (chapter 4), but a clear name makes the loop read like English.

After the loop

The loop variable keeps the last value it had:

123for name in ["Sunny", "Rocky", "Lucky"]:
    pass
print(name)

pass means "do nothing". A block can't be empty, so pass fills the gap.

A common mistake

Printing the list instead of the loop variable prints the whole list every time:

123names = ["Sunny", "Rocky"]
for name in names:
    print(names)

names is the whole list. name is the one item for this iteration. One letter makes all the difference!

The loop variable holds the current item; use it inside the block.

Practice: for loop

Solve these to lock in what you learned in this topic. Each one runs in your browser.

1. 80.Python Program to Print Each Letter of a WordEasySolve
2. 81.Python Program to Remove Spaces from a SentenceMediumSolve