README.md

Templates Basics (Python)

This module introduces generic programming with type hints and reusable classes.

Learning Metadata

• Difficulty: Intermediate.
• Estimated Time: 35-50 minutes.
• Prerequisites: 01-foundations/functions, 03-advanced/structs-and-classes.
• Cross-Language Lens: Compare C++ templates with C# generics, Go type parameters, and Python's runtime flexibility.

Quick Run

python example/main.py

Topics Covered

• Generic functions through type variables.
• Generic classes with reusable element types.
• Type-independent logic with consistent interfaces.
• When type hints clarify constraints even in a dynamic language.

Common Pitfalls

• Assuming type hints enforce runtime behavior by themselves.
• Replacing clear generic APIs with Any too early.
• Ignoring value constraints when writing supposedly reusable code.

Cross-Language Notes

• Compared with C++, this concept broadens from templates into each language's own reusable generic abstraction model.
• Relative to Go and C#, TypeScript generics stay expressive without runtime specialization, while Python treats the same idea more informally.
• The useful comparison is how each language generalizes logic without abandoning type clarity.

Exercise Focus

• exercises/01.py: generic swap function.
• exercises/02.py: generic average over numeric lists.

Exercise Specs

1. exercises/01.py

• Input: two values of the same type.
• Output: values before and after swap.
• Edge cases: identical values; negative numbers.

2. exercises/02.py

• Input: numeric sequence.
• Output: arithmetic average.
• Edge cases: empty list should return 0; mixed positive/negative values.

Checkpoint

• I can write and call generic helper functions with type variables.
• I can create simple generic classes.
• I can identify where type hints help clarify generic code.
• I completed exercises/01.py.
• I completed exercises/02.py.