main.py

from enum import Enum
from typing import List, Optional
from fastapi import FastAPI, Query
from pydantic import BaseModel


class ModelName(str, Enum):
    alexnet = "alexnet"
    resnet = "resnet"
    lenet = "lenet"


class Item(BaseModel):
    name: str
    description: Optional[str] = None
    price: float
    tax: Optional[float] = None


app = FastAPI()


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


fake_items_db = [{"item_name": "Foo"}, {
    "item_name": "Bar"}, {"item_name": "Baz"}]


# When you declare other function parameters that are not part of the path parameters, they are automatically interpreted as "query" parameters.
# @app.get("/items/")
# async def read_item(skip: int = 0, limit: int = 10):
#     return fake_items_db[skip: skip+limit]


# Query Parameters and String Validations
# @app.get("/items/")
# async def read_items(q: str = Query(..., min_length=3)):
#     results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
#     if q:
#         results.update({"q": q})
#     return results


# Optional parameters
# @app.get("/items/{item_id}")
# async def read_item(item_id: str, q: Optional[str] = None, short: bool = False):
#     item = {"item_id": item_id}
#     if q:
#         item.update({"q": q})
#     if not short:
#         item.update(
#             {"description": "This is an amazing item that has a long description"}
#         )
#     return item


# Required query parameters
@app.get("/items/{item_id}")
async def read_user_item(item_id: str, needy: str):
    item = {"item_id": item_id, "needy": needy}
    return item


# Order matters
@app.get("/users/me")
async def read_user_me():
    return {"user_id": "the current user"}


@app.get("/users/{user_id}")
async def read_user(user_id: str):
    return {"user_id": user_id}


# Multiple path and query parameters
@app.get("/users/{user_id}/items/{item_id}")
async def read_user_item(user_id: int, item_id: str, q: Optional[str] = None, short: bool = False):
    item = {"item_id": item_id, "owner_id": user_id}
    if q:
        item.update({"q": q})
    if not short:
        item.update(
            {"description": "This is an amazing item that has a long description"}
        )
    return item


# Query parameter list / multiple values
@app.get("/items/")
async def read_items(
    q: Optional[List[str]] = Query(
        None,
        title="Query string",
        description="Query string for the items to search in the database that have a good match",
        min_length=3
    )
):
    query_items = {"q": q}
    return query_items


@app.get("/model/{model_name}")
async def get_model(model_name: ModelName):
    if model_name == ModelName.alexnet:
        return {"model_name": model_name, "message": "Deep Learning FTW!"}

    if model_name.value == "lenet":
        return {"model_name": model_name, "message": "LeCNN all the images"}

    return {"model_name": model_name, "message": "Have some residuals"}


# Path parameters containing paths
@app.get("/files/{file_path:path}")
async def read_file(file_path: str):
    return {"file_path": file_path}


@app.post("/items/")
async def create_item(item: Item):
    item_dict = item.dict()
    if item.tax:
        price_with_tax = item.price + item.tax
        item_dict.update({"price_with_tax": price_with_tax})
    return item_dict


# Request body + path parameters
@app.post("/items/{item_id}")
async def create_item(item_id: int, item: Item):
    return {"item_id": item_id, **item.dict()}


# Request body + path + query parameters
@app.put("/items/{item_id}")
async def create_item(item_id: int, item: Item, q: Optional[str] = None):
    result = {"item_id": item_id, **item.dict()}
    if q:
        result.update({"q": q})
    return result