Developing Cross-Platform Applications with Python

---
name: Developing Cross-Platform Applications with Python
description: Strategies for writing Python code that runs seamlessly across different platforms, ensuring compatibility and performance.
category: Python Cursor Rules
version: "1.0"
globs:
  - "**/*.py"
triggers:
  - file_open
  - file_save
---

# Cross-Platform Development Guidelines

## 1. Use Standard Libraries

- **Guideline**: Utilize Python's standard libraries, such as `os` and `sys`, to ensure consistent behavior across platforms.
- **Example**:
  ```python
  import os

  file_path = os.path.join("my_directory", "my_file.txt")
  with open(file_path, 'w') as f:
      f.write("Hello, World!")
  ```

## 2. Handle File Paths Appropriately

- **Guideline**: Use `os.path` functions like `os.path.join` and `os.path.abspath` to create file paths that are compatible across different operating systems.
- **Example**:
  ```python
  import os

  path = os.path.join("documents", "file.txt")
  full_path = os.path.abspath(path)
  print(full_path)  # Output will be OS-specific correct path
  ```

## 3. Manage Line Endings

- **Guideline**: When reading or writing files, handle line endings by using the `newline` parameter in the `open` function to ensure consistency across platforms.
- **Example**:
  ```python
  with open("my_file.txt", 'r', newline='') as f:
      content = f.read()
  ```

## 4. Use Virtual Environments

- **Guideline**: Employ virtual environments to manage dependencies and maintain consistency across different development environments.
- **Example**:
  ```bash
  python -m venv myenv
  source myenv/bin/activate  # On macOS/Linux
  myenv\Scripts\activate     # On Windows
  ```

## 5. Test on Multiple Platforms

- **Guideline**: Test your code on all intended platforms to identify and resolve platform-specific issues. Utilize virtual machines or cloud services to facilitate testing.

## 6. Use Cross-Platform Libraries

- **Guideline**: Leverage libraries designed for cross-platform compatibility, such as `requests` for HTTP requests and `Pillow` for image processing.
- **Example**:
  ```python
  import requests

  response = requests.get("https://api.example.com/data")
  data = response.json()
  print(data)
  ```

## 7. Be Mindful of OS-Specific Code

- **Guideline**: When OS-specific code is necessary, use `sys.platform` to conditionally execute code based on the operating system.
- **Example**:
  ```python
  import sys

  if sys.platform.startswith("win"):
      # Windows-specific code
  elif sys.platform.startswith("linux"):
      # Linux-specific code
  elif sys.platform == "darwin":
      # macOS-specific code
  ```

## 8. Follow PEP 8 Standards

- **Guideline**: Adhere to PEP 8 style guidelines to ensure code readability and maintainability.
- **Example**:
  ```python
  # Correct:
  def calculate_area(radius):
      return 3.14 * radius ** 2

  # Incorrect:
  def calculateArea(radius):
      return 3.14*radius**2
  ```

## 9. Implement Comprehensive Testing

- **Guideline**: Write unit tests for all new components and utilities, aiming for at least 80% test coverage.
- **Example**:
  ```python
  import unittest

  class TestMathOperations(unittest.TestCase):
      def test_addition(self):
          self.assertEqual(2 + 2, 4)

  if __name__ == '__main__':
      unittest.main()
  ```

## 10. Document Your Code

- **Guideline**: Use docstrings to document functions, classes, and modules, providing clear explanations of their purpose and usage.
- **Example**:
  ```python
  def add_numbers(a, b):
      """
      Add two numbers and return the result.

      Parameters:
      a (int): The first number.
      b (int): The second number.

      Returns:
      int: The sum of the two numbers.
      """
      return a + b
  ```