# FastAPI usage note
### Installation

$pip install fastapi
$pip install "uvicorn[standard]"

# Simplest Example

- create a main.py

from fastapi import FastAPI
app = FastAPI()

@app.get("/")
async def root():
    return {"message": "Hello World"}

run main.py with following commod

$uvicorn main:app --reload

- main.py can also be create like this

from fastapi import FastAPI
import uvicorn

app = FastAPI()

@app.get("/")
async def root():
    return {"message": "Hello World"}

if __name__ == '__main__':
    uvicorn.run("main:app", port=8000,reload=True)

run main.py with following commod

$python main.py

## Running Screen

INFO:     Will watch for changes in these directories: ['/fastAPI']
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [53822] using WatchFiles
INFO:     Started server process [53827]
INFO:     Waiting for application startup.
INFO:     Application startup complete.

## Web Screen
Open your browser and enter the following URL: http://127.0.0.1:8000/
You will see a webpage with this appearance

---
## Interactive API docs
FastAPI will auto create the api Document at http://127.0.0.1:8000/

# running on specifying host and port

$uvicorn main:app --host 0.0.0.0 --port 80 

or in main.py

if __name__ == '__main__':
    uvicorn.run("main:app", host='0.0.0.0', port=8000,reload=True)

$python main.py

# GET Request

@app.get("/get_number/{number}") 
async def read_number(number: int):
    return {"number": number}

## Send get request
## Return Value

# POST Request
### Installation

$pip install pydantic

## create data model from BaseModel

from fastapi import FastAPI
from pydantic import BaseModel

# create data model
class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None

@app.post("/items/")
async def create_item(item: Item):
    return item

## Send get request

## Return Value