✏️ Code Style & Standards

Consistent code style ensures that the LIMO Pro + MyCobot + YOLO project remains readable, maintainable, and safe.
This guide defines standards, documentation rules, testing requirements, and best practices.

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📐 Style & Formatting

We follow PEP 8 for Python with a few ROS2-specific conventions:

• 4-space indentation (no tabs).
• Snake_case for variables/functions: object_detected, navigate_to_pose_msg().
• PascalCase for class names: PickNode, ExplorationNode.
• ALL_CAPS for constants: WAYPOINTS, PICK_TIMEOUT.
• Imports grouped: standard libs → ROS2 → project modules.

# ✅ Example
import math
import time

import rclpy
from rclpy.node import Node

from .utils import quat_from_yaw

Avoid

• Long functions (>50 lines) — split into smaller methods.
• Magic numbers — use constants or parameters.
• Hardcoded paths — pass via ROS2 parameters.

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📄 Documentation Requirements

Every node, class, and function must have docstrings explaining its purpose.

Example:

class PickNode(Node):
    """
    Controls the MyCobot arm to pick an object.

    Sequence:
    1. Open gripper
    2. Move to center
    3. Move to pickup pose
    4. Close gripper
    5. Return to center
    """

• Use inline comments to explain non-obvious math (e.g., yaw calculations, TF transforms).
• In launch files, comment why a delay exists (TimerAction), not just the value.

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🧪 Testing Guidelines

Unit Tests

• Test individual functions (e.g., quat_from_yaw()).
• Mock ROS2 publishers/subscribers when possible.
• Use pytest for automated testing.

Integration Tests

• Run colcon build && colcon test before merging.
• Test end-to-end:
  1. Start full_system.launch.py
  2. Verify YOLO detects in /yolo/annotated
  3. Confirm /target_pose triggers navigation.

Hardware Tests

• Test arm motions with clear workspace to prevent collisions.
• For navigation, run in a safe, obstacle-free area first.

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💡 Best Practices

• Fail safely — if a node crashes, it should not leave motors running.
• Voice feedback for key states (pick complete, drop complete, navigation start).
• Use ROS2 parameters instead of editing code for configuration.
• Log at appropriate levels:
  • self.get_logger().info() → normal operation
  • self.get_logger().warn() → recoverable issue
  • self.get_logger().error() → critical failure
• Keep launch dependencies modular — avoid one giant launch file for everything.

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✅ Pre-Merge Checklist

• ☐ Code builds with colcon build --symlink-install
• ☐ No PEP8 violations (flake8 clean)
• ☐ All tests pass
• ☐ Code reviewed by at least one other contributor
• ☐ No debug prints left (print() → use logger)

Pro Tip

Run black . && isort . before committing to auto-format your Python code.

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Next: Testing Framework