one-class-per-file.mdc

---
description:
globs:
alwaysApply: true
---
# One Class Per File

Each Python file should contain exactly one class, and the file name should follow the class name convention.

## File Naming Rules

1. For regular classes:
   - Use PascalCase (camelCase with first letter capitalized)
   - File name must match the class name exactly
   - Example: `Genre.py` for `class Genre`

2. For serializer classes:
   - Use concise camelCase
   - File name should be shorter than the class name
   - Example: `genre.py` for `class GenreSerializer`

## Examples

Good examples:
```
# Genre.py
class Genre(models.Model):
    name = models.CharField(max_length=100)
    uuid = models.UUIDField()

# genre.py
class GenreSerializer(serializers.ModelSerializer):
    class Meta:
        model = Genre
        fields = [Fields.NAME, Fields.UUID]

# GenreTree.py
class GenreTree:
    def __init__(self, root: Genre):
        self.root = root
```

Bad examples:
```
# genre_model.py (Bad - should be Genre.py)
class Genre(models.Model):
    pass

# GenreSerializer.py (Bad - should be genre.py)
class GenreSerializer(serializers.ModelSerializer):
    pass

# models.py (Bad - contains multiple classes)
class Genre(models.Model):
    pass

class Artist(models.Model):
    pass
```

## Guidelines

1. Each file must contain exactly one class
2. File name must match the class name convention
3. Keep related classes in the same directory
4. Use `__init__.py` to expose classes
5. Follow the naming convention consistently across the project

## Benefits

- Improves code organization
- Makes files easier to find
- Simplifies version control
- Makes refactoring easier
- Improves code readability
- Makes imports clearer