Why does 0.1 + 0.2 not equal 0.3 in Python?
Why Python prints 0.30000000000000004 for 0.1 + 0.2, why 0.1 + 0.2 == 0.3 is False, and the three fixes: round for display, math.isclose() instead of ==, and Decimal for money. With code you can run.
PythonCourse 1 of 3 · Python from Scratch
The Workbench
Python fundamentals: variables, data types, operators, strings, and your first working scripts.
- No coding experience needed
- Browser editor or VS Code
- Certificate when you finish all 3 courses
Course overview
What you'll learn
- Set up Python and VS Code, try the REPL, write and run your first script, and learn to read error messages.
- Store values in variables, meet int, float, str and bool, and build a small shop calculator.
- f-strings, slicing and string methods, then an interactive greeter that talks to the user.
- Four practice labs, the course quiz, and your own Personal Info Card program.
Who this course is for
- Complete beginners: you need no coding experience.
- You learn best by writing the code yourself, not by watching videos.
- You want feedback on your own code, at your own pace, one hour at a time.
- You would rather start in the browser than install tools first.
Course syllabus
Each session is one hour with the AI tutor and uses one credit. Sign in to start.
Session 1Your First Python ScriptSet up Python and VS Code, try the REPL, write and run your first script, and learn to read error messages.
- Welcome and setup10 min
- The interactive shell, the REPL10 min
- Your first script10 min
- Comments and errors10 min
- Mini project: your "about me" card10 min
- Final check and wrap-up10 min
Session 2Variables, Types & OperatorsStore values in variables, meet int, float, str and bool, and build a small shop calculator.
- Welcome back and warm-up10 min
- Variables and naming10 min
- Core data types and conversion10 min
- Arithmetic operators10 min
- Comparison and logical operators10 min
- Final check and wrap-up10 min
Session 3Strings & Input/Outputf-strings, slicing and string methods, then an interactive greeter that talks to the user.
- Welcome back and warm-up10 min
- Creating and joining strings10 min
- f-strings10 min
- Indexing, slicing and string methods10 min
- input() and the greeter project10 min
- Final check and wrap-up10 min
Session 4Practice Lab & CapstoneFour practice labs, the course quiz, and your own Personal Info Card program.
- Welcome back and warm-up10 min
- Lab A, temperature converter10 min
- Lab B and Lab C, tip calculator and Mad Libs10 min
- Lab D, string inspector, and the quiz10 min
- Course capstone, Personal Info Card10 min
- Final check and wrap-up10 min
How the tutor teaches
The same three rules in every session, from the first line of code to the last.
Practice, not videos
You write all of the code. The tutor reacts to what you actually typed, line by line.
Hints, not answers
A ladder from a light nudge to the solution, and only after you have made a real attempt.
Real output, never invented
Your code runs for real. The tutor reads what the machine showed, and trusts it.
Keep the momentum going
The next course of Python from Scratch, and where the other paths begin.
Errors you may meet in this course
Python TypeError: unsupported operand type(s) for -: 'int' and 'str' (or 'str' and 'int')
Why Python says unsupported operand type(s) for -, +, / or //: 'int' and 'str' (or 'str' and 'int'), why input() always gives you text, and how to fix it with int(). With code you can run.
Frequently asked questions
What students ask before they start The Workbench.
Do I need to install anything?
Not for this course. The editor in the page runs your code next to the chat. If you prefer, you can use VS Code on your own computer.
What if I get stuck?
The tutor gives a ladder of hints, from a light nudge to the solution, and only after you have made a real attempt.
Do I keep my code?
Yes. In the editor in the page, your project is saved on the server for this course, continues in your next session on any device, and downloads as a .zip.
Do I get a certificate?
Yes, for the whole path. When you have finished all 3 courses of Python from Scratch (this is Course 1), you get the Python from Scratch certificate of completion with your name: a link anyone can check, one-click LinkedIn and a PDF. Your progress towards it is on your dashboard.
Do I need anything from before?
No. This course starts from zero. Take the sessions in order: each one builds on the one before.
Write your first program in the next 20 minutes.
Twenty minutes with the tutor, right in your browser. No card, nothing to install.
Start the free trial