Fast API Naming Conventions

Pythong Naming Convention

Sure, here’s a table showing the standard naming conventions for Python code, based on PEP 8`, the official style guide for Python:

Type	Naming Convention	Example
Variable	Snake case	my_variable
Function	Snake case	my_function()
Class	Pascal case	MyClass
Constant	All uppercase with underscores	MY_CONSTANT
Module	Short, lowercase names. Can have underscores	my_module.py
Package	Short, lowercase names. Should not have underscores	mypackage
Method	Snake case	my_method()
Instance variable	Snake case (beginning with underscore if private)	_my_instance_var or my_instance_var
Global variable	Snake case	my_global_var
Factory function	(returns instance of a class) should be named like classes	FactoryFunction()

FastAPI Naming Convention

• FastAPI is a Python-based framework, so most of the general Python naming conventions apply

• However, FastAPI also uses Pydantic for data validation which pushes it’s own conventions over Python convention

• So, following table shows Python vs FastAPI Conventions, highlighting the similarity & difference among the 2:

Type	Python Naming Convention	Example	FastAPI Naming Convention	Example	Similar/Different
Variable	Snake case	user_name	Snake case	user_name	Similar
Function	Snake case	def get_user():	Snake case	def get_user():	Similar
Class	PascalCase	class User:	Snake case for Pydantic models, PascalCase otherwise	Pydantic model - class user:, Others - class User:	Different
Constant	All uppercase with underscores	MAX_LIMIT	All uppercase with underscores	MAX_LIMIT	Similar
Module	Short, lowercase names. Can have underscores	user_model.py	Short, lowercase names. Can have underscores	user_model.py	Similar
Package	Short, lowercase names. Should not have underscores	mypackage	Short, lowercase names. Should not have underscores	mypackage	Similar
Method	Snake case	def get_user():	Snake case	def get_user():	Similar
Instance Variable	Snake case (beginning with underscore if private)	_user_name	Snake case (beginning with underscore if private)	_user_name	Similar
Global Variable	Snake case	total_users	Snake case	total_users	Similar
Endpoint Parameters	N/A	N/A	Snake case	@app.get("/users/{user_id}")	N/A
Path Operations	N/A	N/A	Snake case	@app.get("/get_users")	N/A
Pydantic Model	N/A	N/A	PascalCase	class UserModel:	N/A
Pydantic Field	N/A	N/A	Snake case	user_name: str in a Pydantic model	N/A

Note that endpoint parameters, path operations, Pydantic models and Pydantic fields are specific to FastAPI and don’t have a corresponding Python convention.

JSON Conventions for RestAPI

Sure, here’s the updated table:

Component	Convention	Example
Resource Name	Plural form, lowercase	/creditCards
Path Parameters	Lowercase, represents resource identifier	/creditCards/123
Query Parameters	camelCase, used for filtering/sorting/field selection	/creditCards?sortBy=cardType&order=desc
Body Parameters	camelCase	{ "cardHolderName": "John Doe", "cardNumber": "1234567812345678", "expiryDate": "12/24" }
Headers	PascalCase (camelCase with first letter capitalized)	{ "Content-Type": "application/json", "Authorization": "Bearer abc123" }

Covenstion Issues

Let’s summarize the naming convention for Application vs API:

• RestAPI - Primarily camelCase
• FastAPI - Primarily snake_case

By default, FastAPI api parameters are defined in snakecase & thus, reflected as is in API’s breaking RestAPI naming convention

Post for Better Explanation of the issue

Resolution