Python Classroom notes 11/Aug/2026

Lets build our first api’s

Lets Build apis for inventory

• Identify nouns and verbs
  • Product
    • Get
    • update
    • delete
    • Create
  • Sale(Order)
    • Create
    • Get
    • Delete
  • Procurement
    • Create
    • Get
    • Delete
  • Vendor
    • Get
    • update
    • delete
    • Create
  • Customer
    • Get
    • update
    • delete
    • Create
  • Employee
    • Get
    • update
    • delete
    • Create

To build this lets use Fastapi

• Create a folder called as hello-api
• lets add dependencies Refer Here

uv init .
uv add fastapi[standard]

• Now create an application object with simple code

from fastapi import FastAPI

# create an application object
app = FastAPI()

@app.get("/")
def home():
    return "Welcome to my API"

• From the terminal run uv run fastapi dev main.py

• To debug watch classroom video.

• Basic code

from fastapi import FastAPI

# create an application object
app = FastAPI()

@app.get("/")
def home():
    return "Welcome to my API"

@app.get("/products")
def get_products():
    return [
        {"id": 1, "name": "Laptop"},
        {"id": 2, "name": "Mouse"}
    ]

@app.post("/products")
def add_product(id:int, name: str):
    return {"id": id, "name": name}

@app.put("/products/{id}")
def update_product(id:int, name:str):
    return {"id": id, "name": name}

@app.get("/customers")
def get_customers():
    return [
        {"id": 1, "name": "John"},
        {"id": 2, "name": "Jane"}
    ]

@app.delete("/products/{id}")
def delete_product(id: int):
    raise NotImplementedError()

• Ideal status codes: Use llm

• Define models and have some validations and different ways of sending data

• Exercise:

  • Try creating the same api with title inventory and version 1.0.0.0
  • For all create methods change default status code to 201 and for all delete change the status code to 204
  • Try build a client for this api using requests.