Fill-In Challenges

Exercises where function stubs are provided — you write the implementation.

How It Works

1. Open the exercise file. You will see functions with docstrings and # YOUR CODE HERE markers.
2. Read the docstring carefully — it tells you exactly what the function should do, what arguments it takes, and what it returns.
3. Replace # YOUR CODE HERE with your implementation.
4. Run the tests to check your work:

pytest tests/test_01.py -v

1. If stuck, check solutions/ for the completed code with explanations.

Exercise List

File	Topic	Difficulty
01_list_filter.py	Filtering lists by criteria	Beginner
02_dict_builder.py	Building dicts from parallel lists	Beginner
03_file_reader.py	Parsing structured text files	Intermediate
04_string_formatter.py	String formatting and alignment	Intermediate
05_basic_class.py	Classes, __init__, __str__, methods	Intermediate
06_error_handler.py	Try/except, multiple error types	Intermediate

Tips

• Read the docstring before writing any code.
• Run the tests frequently — they tell you exactly what is expected.
• Start with the simplest function in each file and work your way up.
• The tests are not trick questions — if your logic is sound, they will pass.