Naming Functions Related to Routes

The most common practice, often seen in FastAPI’s official documentation, is to use a verb_resource or action_resource pattern, where:

1. verb / action: Describes the operation performed by the route, often aligned with CRUD verbs (Create, Read, Update, Delete) or specific actions.
   • read_: for GET operations (reading one or more items).
   • create_: for POST operations (creating a new item).
   • update_: for PUT or PATCH operations (updating an existing item).
   • delete_ (or remove_): for DELETE operations (deleting an item).
   • Other descriptive verbs for specific actions (e.g., search_, upload_, login_, process_).
2. resource: describes the entity or resource the route operates on (generally singular for operations on a single item, plural for operations on collections).
   • item, items
   • user, users
   • order, orders
   • product, products

Practical Examples:

• GET /items/: reads a collection of items.
  • Recommended function name: read_items
• GET /items/{item_id}: reads a single specific item.
  • Recommended function name: read_item
• POST /items/: creates a new item.
  • Recommended function name: create_item
• PUT /items/{item_id}: completely updates an item.
  • Recommended function name: update_item
• PATCH /items/{item_id}: partially updates an item.
  • Recommended function name: patch_item (or sometimes update_item is also used for PATCH)
• DELETE /items/{item_id}: deletes an item.
  • Recommended function name: delete_item
• POST /users/{user_id}/avatar: uploads an avatar for a specific user.
  • Recommended function name: upload_user_avatar
• POST /token: generates an access token (login).
  • Recommended function name: login_for_access_token or create_access_token
• GET /products/search: searches for products.
  • Recommended function name: search_products

Additional rules and good practices:

• PEP 8: always follow Python’s PEP 8 style conventions, so use snake_case (lowercase words separated by underscores) for function names.
• Clarity: the name should immediately make the function’s purpose clear in relation to its route. If you see def read_item(...), it should be obvious that it handles a request to read a single item.
• Consistency: the most important thing is to choose one convention (preferably the one described above) and apply it consistently throughout the project. This makes the code predictable and easy for you and other developers to navigate.
• Avoid Generic Names: names like handle_request, process_data, or endpoint1 are too generic and should be avoided.

In conclusion: the “rule” to follow is the verb_action_resource convention in snake_case, applied with consistency, because it maximizes the readability and maintainability of your FastAPI code.