Python lesson 6

For Loops

Loop through every letter or item. Let Python do the stepping!

Loop Through a String

You can use a for loop to visit every character in a string, one at a time. Python steps through each letter automatically. You just write what to do with each one!

for char in "hello":
print(char) → h e l l o (one per line)

for char in "hello":
    print(char)

One Letter At A Time

for letter in "cat":
    print(letter)

Loop Through Letters

Click Run to see Python print each letter in "Python" one at a time!

Hint: Click Run! The loop visits every letter in the word "Python" one at a time.

for char in "Python":
    print(char)

Loop Through Your Name

Change "Alex" to YOUR name and run. See each letter printed on its own line!

Hint: Change "Alex" to your own name, then click Run to see your letters one by one!

name = "Alex"
for char in name:
    print(char)

Loop with If

You have used in to walk through things: for char in word. It has a second job. Between two things, char in "aeiouAEIOU" asks a question: is this character one of those? Run this to see only the vowels in a word, then try changing "Python" to another word.

Hint: The if asks whether the character is inside the string of vowels. That is what in means here, which is a different job from the in that walks through a word. Change "Python" to another word.

word = "Python"
for char in word:
    if char in "aeiouAEIOU":
        print(char, "is a vowel")

What you can do on CodeIt

Run the example, change one part, and use the result to check your understanding before moving to the next lesson.