Add project coding standards and guidelines for Python (PEP 8)

.github/copilot-instructions.md

@@ -0,0 +1,71 @@
+---
+applyTo: "**"
+---
+
+# Project General Coding Standards (Python - PEP 8)
+
+## Naming Conventions
+
+- Follow PEP 8 naming conventions strictly
+- Use `snake_case` for variables, functions, and methods
+- Use `PascalCase` for class names
+- Use `UPPER_CASE` for constants
+- Prefix internal/private attributes with a single underscore (`_`)
+- Avoid single-letter variable names unless in very small scopes (e.g., loops)
+
+---
+
+## Code Style & Formatting
+
+- Follow PEP 8 guidelines for formatting
+- Use 4 spaces for indentation (never tabs)
+- Limit lines to 79 characters when possible (max 88 if using Black)
+- Add a blank line between logical sections of code
+- Keep imports organized:
+  1. Standard library
+  2. Third-party packages
+  3. Local imports
+- Avoid wildcard imports (`from module import *`)
+- Remove unused imports and variables
+
+---
+
+## Clean Code Principles
+
+- Write small, focused functions that do **one thing only**
+- Prefer functions over long procedural blocks
+- Keep functions under ~30 lines when possible
+- Use descriptive and meaningful names
+- Avoid code duplication (DRY principle)
+- Prefer explicit code over implicit behavior
+- Avoid deeply nested logic (max 2–3 levels)
+- Use early returns to reduce nesting
+- Keep classes focused and cohesive
+- Write code that is easy to read and maintain
+
+---
+
+## Function Design
+
+- Always use functions when logic can be reused or isolated
+- Add type hints to all function signatures
+- Keep functions pure when possible (avoid side effects)
+- Document functions using docstrings (PEP 257 style)
+
+Example:
+
+```python
+def calculate_average(values: list[float]) -> float:
+    """
+    Calculate the average of a list of numbers.
+
+    Args:
+        values: A list of float numbers.
+
+    Returns:
+        The arithmetic mean of the values.
+    """
+    if not values:
+        raise ValueError("The values list cannot be empty.")
+
+    return sum(values) / len(values)