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The Code Refinery

Turn a plan into a working program: break problems down, write readable Python, and track down syntax, logic and runtime errors.

⏱️ 18 min 🎯 14 activities Teachers Not yet rated Students Not yet rated

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What you'll cover

Refining your code 🛠️

Writing a program is only the start. **Refining** code means making it clear and correct: breaking problems down, writing readable code, and tracking down errors. This module uses short **Python 3** examples.

Key terms 📖

Learn these before you begin:

Match each idea to its description

  • Syntax error
  • Logic error
  • Runtime error
  • Readability
  • Breaks the rules of the language
  • Runs but gives the wrong output
  • Crashes while the program is running
  • Making code easy for people to read

Name the error

A programmer forgets the colon at the end of an 'if' line in Python, so the code will not run. What type of error is this?

  • A syntax error
  • A logic error
  • A runtime error
  • No error at all

Readable code 📐

Readable code is easier to understand and fix. Good habits: - Use **meaningful identifiers** (a name like total, not t). - **Indent** code inside loops and if-statements. - Add **comments** to explain tricky parts. - Use **white space** and blank lines to group ideas.

Readable code

Select the TWO techniques that make code more readable.

  • Using meaningful variable names
  • Adding comments to explain the code
  • Putting the whole program on one long line
  • Naming every variable x

Breaking problems down 🧩

Two ideas help you tackle big problems. **Decomposition** means breaking a problem into smaller sub-problems you can solve one at a time. **Abstraction** means hiding unnecessary detail so you focus on the key parts. A flowchart or pseudocode is an abstraction: a plan for the code before you write it.

Match each technique to its meaning

  • Decomposition
  • Abstraction
  • Pseudocode
  • Refining code
  • Breaking a problem into smaller parts
  • Hiding unnecessary detail
  • A plain-language plan for a program
  • Improving code that already works

Developing a program

An interactive activity.

Readable code frame

Good code uses meaningful _____, so a total is called total not t. Code inside a loop is _____ to show it belongs there. A _____ explains tricky code to a reader. Code that breaks the rules of the language gives a _____ error.

identifiers indented comment syntax numbers deleted loop logic

Name the error

A program runs all the way to the end but prints the wrong average. What type of error is this?

  • A logic error
  • A syntax error
  • A runtime error
  • A readability error

Techniques and errors frame

Breaking a problem into parts is called _____. Hiding detail to focus on the key parts is _____. An error that crashes the program while it runs is a _____ error. An error that runs but gives the wrong output is a _____ error.

decomposition abstraction runtime logic iteration selection syntax comment

Classify the error

An interactive activity.

Explain good practice

An interactive activity.