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Python, Java, C and Linux, right in your browser.
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1names = ["Tommy", "Lance", "Cortez"]2for i in range(0, len(names)):3 print(f"Hero number {i + 1}: {names[i]}")
- 4courses
- 211lessons
- 72algorithm challenges
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Run it against tests
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How can we tell the computer "hey, I like pizza"? In Python we say:
1print("hey, I like pizza")
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Read a lesson
Short, with examples you can run.
Python · PrintHow can we tell the computer "hey, I like pizza"? In Python we say:
1print("hey, I like pizza")Outputhey, I like pizzaWrite code in your browser
Nothing to install.
main.py▶ Run1for star in ["Sirius", "Vega", "Rigel"]:2 print(star)OutputSirius Vega RigelRun it against tests
Know right away if it works.
Accepted35 / 35- Test 1
- Test 2
- Test 3 (hidden)
- Test 4 (hidden)
- Test 5 (hidden)
- Test 6 (hidden)
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Watch an algorithm, step by step
Lessons show you how an algorithm works, one move at a time.
What's inside
Courses
Python, Java, C and Linux, from your first print to processes and threads, one short lesson at a time.
Linux terminal
A real terminal right in the page, with missions to solve on a machine of your own.
Laniakea, a space game
Every Python lesson you finish becomes a planet. Fly to it and pass a 10-question test on the lesson to conquer it.
- Python60 lessons
- Java49 lessons
- C47 lessons
- Linux55 lessons
Algorithm challenges
Challenges from easy to hard, graded against hidden tests, with your runtime next to the reference.
The forum
Ask when you are stuck and help when you are not; the answer that worked gets marked as the solution.
An AI tutor
It points you at the idea and lets you find the fix yourself, without handing you the answer.
Courses
Python, Java, C and Linux, from your first print to processes and threads, one short lesson at a time.
- Python60 lessons
- Java49 lessons
- C47 lessons
- Linux55 lessons
Algorithm challenges
Challenges from easy to hard, graded against hidden tests, with your runtime next to the reference.
- ✓Reverse a Stringeasy
- ✓Palindrome Checkeasy
- ✓Caesar Ciphermedium
- 4Two Summedium
- 5Group Anagramshard
Linux terminal
A real terminal right in the page, with missions to solve on a machine of your own.
student@sandbox:~$ pwd/home/studentstudent@sandbox:~$ lsmission.txt reports toolsstudent@sandbox:~$ ls reportsjanuary.log february.logstudent@sandbox:~$The forum
Ask when you are stuck and help when you are not; the answer that worked gets marked as the solution.
Maria21How do I print my name 3 times?Marco HoegerSolvedWith a for loop:1for i in range(3):2 print("Maria")- BetaAfter the first 6 Python lessons
Laniakea, a space game
Every Python lesson you finish becomes a planet. Fly to it and pass a 10-question test on the lesson to conquer it.
What does this print?1print("5 + 3")85 + 3 An AI tutor
It points you at the idea and lets you find the fix yourself, without handing you the answer.
Why does my loop print 0, 1, 2 and not 1, 2, 3?range(3) starts counting at 0, so you get three numbers ending at 2. range can also take a number to start from: which one would give you 1, 2, 3?
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Questions
- No. Read, write and run code without one. An account lifts the ten-run limit, saves your progress and opens the forum and the AI tutor.
- Yes. There is no paid plan and no card to add, and the CyberStars code is public on GitHub, so anyone can check it.
- Python, if you've never programmed.
- No. Everything runs in your browser.
- Yes, though a bigger screen is more comfortable.
- Yes, the site and every lesson. Switch with EN and RO at the top.