FastAPI

• start
• hello world
• rest
• rest参数
• 请求体
• 参数查询&字符串校验
• 参数列表
• 多参数同时查询
• 路径参数&数值校验
• 表单

---

start

uvicorn main:app --reload

hello world

from fastapi import FastAPI
import uvicorn

app = FastAPI()

# http://127.0.0.1:8000/
@app.get("/")
async def root():
    return {"message": "Hello World"}

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

rest

最基本的路径参数
# http://127.0.0.1:8000/items/1
@app.get("/items/{item_id}")
async def read_item(item_id):
    return {"item_id": item_id} # item_id自定义
    
多个路径参数
# http://127.0.0.1:8000/items/1/2
@app.get("/items/{item_id}/{user_id}")
async def read_item(item_id, user_id):
    return {"item_id": item_id, "user_id": user_id}
    
有类型的路径参数
# http://127.0.0.1:8000/items/1
@app.get("/items/{item_id}")
async def read_item(item_id: int):
    return {"item_id": item_id}
    
文件路径参数
# http://127.0.0.1:8000/file//home/my/my.txt
@app.get("/file/{file_path:path}")
async def read_item(file_path):
    return {"file_path": file_path}

rest参数

带默认值的查询参数
# http://127.0.0.1:8000/items/?skip=0&limit=2
fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]
@app.get("/items/")
async def read_item(skip: int = 0, limit: int = 10):
    return fake_items_db[skip: skip + limit]
    
可选查询参数
# http://127.0.0.1:8000/items/1?q=admin
from typing import Union
@app.get("/items/{item_id}")
async def read_item(item_id: str, q: Union[str, None] = None):
    if q:
        return {"item_id": item_id, "q": q}
    return {"item_id": item_id}
    
多路径多查询参数
# http://127.0.0.1:8000/users/1/items/2
# or 
# http://127.0.0.1:8000/users/1/items/2?q=query&short=true
@app.get("/users/{user_id}/items/{item_id}")
async def read_user_item(
        user_id: int, item_id: str, q: Union[str, None] = 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
    
必需查询参数
# http://127.0.0.1:8000/items/123?needy=yes
@app.get("/items/{item_id}")
async def read_user_item(item_id: str, needy: str):
    item = {"item_id": item_id, "needy": needy}
    return item

请求体

from pydantic import BaseModel
from typing import Union

class Item(BaseModel):
    name: str = '小明'
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None
@app.post("/items/")
async def create_item(item: Item):
    print(item.name)
    return item
    
调用
curl -X 'POST' \
  'http://127.0.0.1:8000/items/' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "name": "小明",
  "description": "string",
  "price": 0,
  "tax": 0
}'

参数查询&字符串校验

from fastapi import Query

@app.get("/items/")
async def read_items(q: Union[str, None] = Query(default=None, max_length=50)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})
    return results

参数列表

default	默认值	任意类型或...
max_length	最大长度	int
min_length	最小长度	int
pattern	正则匹配	string
alias	别名参数	string
deprecated	准备弃用参数	bool

多参数同时查询

# http://127.0.0.1:8000/items/?q=foo&q=bar
@app.get("/items/")
async def read_items(q: Union[List[str], None] = Query(default=None)):
    query_items = {"q": q}
    return query_items

路径参数&数值校验

from fastapi import FastAPI, Path, Query
from typing_extensions import Annotated

@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get")],
    q: Annotated[Union[str, None], Query(alias="item-query")] = None,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})
    return results

参数列表
...	和Query具有相同参数	...
ge	大于等于	int float
gt	大于	int float
le	小于等于	int float
le	小于等于	int float
title	api文档的标题	string

表单

from fastapi import FastAPI, Form
import uvicorn

app = FastAPI()
@app.post("/login/")
async def login(username: str = Form(), password: str = Form()):
    return {"username": username}
if __name__ == '__main__':
    uvicorn.run(app='main:app', reload=True)