571 lines
13 KiB
Markdown
571 lines
13 KiB
Markdown
FastAPI 备忘清单
|
||
===
|
||
|
||
一个用于构建 API 的现代、快速（高性能）的 web 框架，使用 Python 3.6+ 并基于标准的 Python 类型提示
|
||
|
||
入门
|
||
---
|
||
<!--rehype:body-class=cols-2-->
|
||
|
||
### 安装 FastAPI
|
||
|
||
```shell
|
||
$ pip install "fastapi[all]"
|
||
```
|
||
|
||
#### 可以分开来安装
|
||
|
||
假如你想将应用程序部署到生产环境，你可能要执行以下操作：
|
||
|
||
```shell
|
||
$ pip install fastapi
|
||
```
|
||
|
||
并且安装 `uvicorn` 来作为服务器：
|
||
|
||
```shell
|
||
$ pip install "uvicorn[standard]"
|
||
```
|
||
|
||
#### 运行代码
|
||
|
||
```shell
|
||
$ uvicorn main:app --reload
|
||
```
|
||
|
||
Python: `3.9.5` FastAPI: `0.103.1`
|
||
|
||
### 最小程序
|
||
|
||
下面代码会直接启动http服务，也可以使用 `uvicorn main:app --reload`
|
||
|
||
```python
|
||
from fastapi import FastAPI
|
||
import uvicorn
|
||
|
||
app = FastAPI()
|
||
```
|
||
|
||
添加一个 API 的示例
|
||
|
||
```python
|
||
# 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)
|
||
```
|
||
|
||
### 路径参数
|
||
|
||
#### 最基本的路径参数
|
||
|
||
```python
|
||
# 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
|
||
|
||
```python
|
||
# 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
|
||
|
||
```python
|
||
# 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
|
||
|
||
```python
|
||
# 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}
|
||
```
|
||
|
||
### 查询参数
|
||
<!--rehype:wrap-class=row-span-2-->
|
||
|
||
#### 带默认值的查询参数
|
||
|
||
```python
|
||
# http://127.0.0.1:8000/items/?skip=0&limit=2
|
||
fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}]
|
||
|
||
@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
|
||
|
||
```python
|
||
# 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
|
||
|
||
```python
|
||
# 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": "这是一个令人惊叹的项目，有很长的描述"}
|
||
)
|
||
return item
|
||
```
|
||
|
||
#### 必需查询参数
|
||
|
||
```python
|
||
# 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
|
||
|
||
```python
|
||
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
|
||
|
||
```bash
|
||
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
|
||
}'
|
||
```
|
||
|
||
### 查询参数和字符串校验
|
||
|
||
```python
|
||
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
|
||
|
||
| 参数 | 含义 | 类型 |
|
||
| ---------- | ------------ | ------------- |
|
||
| `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` |
|
||
|
||
#### 多个相同的查询参数
|
||
|
||
```python
|
||
# 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
|
||
```
|
||
|
||
### 路径参数和数值校验
|
||
|
||
Path 用法基本和 Query 相同，参考：[FastAPI官方文档](https://fastapi.tiangolo.com/zh/tutorial/path-params-numeric-validations/)
|
||
|
||
#### 导入 Path
|
||
|
||
```python
|
||
from fastapi import FastAPI, Path, Query
|
||
from typing_extensions import Annotated
|
||
```
|
||
|
||
#### 声明元数据
|
||
|
||
```python
|
||
@app.get("/items/{item_id}")
|
||
async def read_items(
|
||
item_id: Annotated[int, Path(title="要获取的项目的 ID")],
|
||
q: Annotated[str | None, Query(alias="item-query")] = None,
|
||
):
|
||
results = {"item_id": item_id}
|
||
if q:
|
||
results.update({"q": q})
|
||
return results
|
||
```
|
||
|
||
#### 参数列表
|
||
|
||
| 参数 | 含义 | 类型 |
|
||
| ----- | ------------------- | --------- |
|
||
| `...` | 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` |
|
||
|
||
### 其他参数
|
||
|
||
都具有 `Query` 的参数，`max_length`、`min_length` 等
|
||
|
||
#### Cookie参数
|
||
|
||
```python
|
||
from fastapi import Cookie
|
||
|
||
@app.get("/items/")
|
||
async def read_items(
|
||
ads_id: Annotated[Union[str, None], Cookie()] = None
|
||
):
|
||
return {"ads_id": ads_id}
|
||
```
|
||
|
||
#### Header 参数
|
||
|
||
```python
|
||
from fastapi import Header
|
||
|
||
@app.get("/items/")
|
||
async def read_items(
|
||
user_agent: Annotated[Union[str, None], Header()] = None,
|
||
items_id: Annotated[Union[int, None], Header(ge=1)] = None
|
||
):
|
||
return {"User-Agent": user_agent, "items_id": items_id}
|
||
```
|
||
|
||
### 表单数据
|
||
|
||
接收的不是 JSON，而是表单字段时，要使用 Form。
|
||
|
||
#### 安装
|
||
|
||
```shell
|
||
$ pip install python-multipart
|
||
```
|
||
|
||
#### HTML
|
||
|
||
```html
|
||
<!DOCTYPE html>
|
||
<html lang="en">
|
||
<head>
|
||
<meta charset="UTF-8">
|
||
</head>
|
||
<body>
|
||
<form method="post" action="http://127.0.0.1:8000/login">
|
||
<span>账号：</span><input type="text" name="username">
|
||
<br>
|
||
<span>密码：</span><input type="password" name="password">
|
||
<br>
|
||
<input type="submit" value="登录">
|
||
</form>
|
||
</body>
|
||
</html>
|
||
```
|
||
|
||
#### FastAPI
|
||
|
||
```python
|
||
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)
|
||
```
|
||
|
||
### 文件上传
|
||
<!--rehype:wrap-class=col-span-2-->
|
||
|
||
```python
|
||
from fastapi import FastAPI, UploadFile
|
||
from fastapi.responses import HTMLResponse
|
||
|
||
@app.post("/uploadfile/")
|
||
async def create_upload_file(file: UploadFile):
|
||
print(file.file.read().decode())
|
||
return {"filenames": file.filename, "type": str(type(file.file))}
|
||
|
||
@app.get("/")
|
||
async def main():
|
||
content = """<body>
|
||
<form action="/uploadfile/" enctype="multipart/form-data" method="post">
|
||
<input name="file" type="file" multiple>
|
||
<input type="submit">
|
||
</form>
|
||
</body>"""
|
||
return HTMLResponse(content=content)
|
||
```
|
||
|
||
#### UploadFile 属性
|
||
|
||
| 属性名 | 含义 | 返回 |
|
||
| ------------ | -------- | --------------------------------------- |
|
||
| `filename` | 文件名 | 上传的文件名 |
|
||
| `content_type` | 内容类型 | `MIME` 类型 |
|
||
| `file` | 文件 | SpooledTemporaryFile 具有 `read`，`write` 方法 |
|
||
<!--rehype:className=left-align-->
|
||
|
||
#### UploadFile async 方法
|
||
|
||
| 方法名 | 含义 |
|
||
| ------------ | ----------------------------------------- |
|
||
| `write(data)` | 把 `data` 写入文件 |
|
||
| `read(size)` | 按指定数量的字节读取文件内容 |
|
||
| `seek(offset)` | 移动至文件 `offset` （`int`）字节处的位置 |
|
||
| `close()` | 关闭文件 |
|
||
<!--rehype:className=left-align-->
|
||
|
||
依赖项
|
||
---
|
||
<!--rehype:body-class=cols-2-->
|
||
|
||
### 依赖项使用场景
|
||
|
||
- 共享业务逻辑（复用相同的代码逻辑）
|
||
- 共享数据库连接
|
||
- 实现安全、验证、角色权限
|
||
- 等……
|
||
|
||
### 创建依赖项
|
||
<!--rehype:wrap-class=row-span-2-->
|
||
|
||
```python
|
||
from typing import Union
|
||
|
||
from fastapi import Depends, FastAPI
|
||
|
||
app = FastAPI()
|
||
```
|
||
|
||
`read_items` 和 `read_users` 方法依赖 `common_parameters`
|
||
白话就是 `read_items` 和 `read_users` 都需要 `q`，`skip`，`limit` 查询参数
|
||
|
||
```python
|
||
async def common_parameters(
|
||
q: Union[str, None] = None,
|
||
skip: int = 0,
|
||
limit: int = 100
|
||
):
|
||
return {"q": q, "skip": skip, "limit": limit}
|
||
|
||
|
||
@app.get("/items/")
|
||
async def read_items(
|
||
commons: dict = Depends(common_parameters)
|
||
):
|
||
return commons
|
||
|
||
|
||
@app.get("/users/")
|
||
async def read_users(
|
||
commons: dict = Depends(common_parameters)
|
||
):
|
||
return commons
|
||
```
|
||
|
||
### 类作为依赖项
|
||
|
||
```python
|
||
from typing import Union
|
||
from fastapi import Depends, FastAPI
|
||
|
||
app = FastAPI()
|
||
fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}]
|
||
|
||
class CommonQueryParams:
|
||
def __init__(
|
||
self,
|
||
q: Union[str, None] = None,
|
||
skip: int = 0,
|
||
limit: int = 100
|
||
):
|
||
self.q = q
|
||
self.skip = skip
|
||
self.limit = limit
|
||
```
|
||
|
||
`read_itemsx` 接收一个 `commons` 参数，类型是 `CommonQueryParams`
|
||
`CommonQueryParams` 接收三个参数，这三个参数是调用 api 的时候传
|
||
|
||
```python
|
||
@app.get("/items/")
|
||
async def read_items(
|
||
commons: CommonQueryParams = Depends(CommonQueryParams)
|
||
):
|
||
response = {}
|
||
if commons.q:
|
||
response.update({"q": commons.q})
|
||
items = fake_items_db[commons.skip : commons.skip + commons.limit]
|
||
response.update({"items": items})
|
||
return response
|
||
```
|
||
|
||
#### 还可以简写
|
||
|
||
```python
|
||
@app.get("/items/")
|
||
async def read_items(
|
||
# 这里的 Depends 没有传参，FastAPI 会自动使用 CommonQueryParams
|
||
commons: CommonQueryParams = Depends()
|
||
):
|
||
response = {}
|
||
if commons.q:
|
||
response.update({"q": commons.q})
|
||
items = fake_items_db[commons.skip : commons.skip + commons.limit]
|
||
response.update({"items": items})
|
||
return response
|
||
```
|
||
|
||
### 子依赖项
|
||
|
||
```python
|
||
from typing import Union
|
||
from fastapi import Cookie, Depends, FastAPI
|
||
|
||
app = FastAPI()
|
||
|
||
def query_extractor(q: Union[str, None] = None):
|
||
return q
|
||
|
||
def query_or_cookie_extractor(
|
||
q: str = Depends(query_extractor),
|
||
last_query: Union[str, None] = Cookie(default=None),
|
||
):
|
||
if not q:
|
||
return last_query
|
||
return q
|
||
|
||
# read_query函数依赖query_or_cookie_extractor函数
|
||
# query_or_cookie_extractor函数又依赖query_extractor函数
|
||
# 就是说依赖项可以依赖其他依赖项，只要你不晕，可以无数次套娃
|
||
@app.get("/items/")
|
||
async def read_query(
|
||
query_or_default: str = Depends(query_or_cookie_extractor)
|
||
):
|
||
return {"q_or_cookie": query_or_default}
|
||
```
|
||
|
||
#### 不使用缓存
|
||
|
||
使用 `use_cache = False` 参数不使用缓存数据，不使用 `use_cache = False`，`value` 和 `value1` 是一样的
|
||
|
||
```python
|
||
def result_value():
|
||
value = randint(1, 99)
|
||
return value
|
||
|
||
def get_value(
|
||
value: int = Depends(result_value, use_cache=False),
|
||
value1: int = Depends(result_value, use_cache=False)
|
||
):
|
||
return value, value1
|
||
|
||
@app.get('/value/')
|
||
async def needy_dependency(value: tuple = Depends(get_value)):
|
||
return {"value": value}
|
||
```
|
||
|
||
### 全局依赖项
|
||
|
||
```python
|
||
from fastapi import Depends, FastAPI, Header, HTTPException
|
||
|
||
async def verify_token(x_token: str = Header()):
|
||
if x_token != "fake-super-secret-token":
|
||
raise HTTPException(status_code=400, detail="X-Token 标头无效")
|
||
|
||
async def verify_key(x_key: str = Header()):
|
||
if x_key != "fake-super-secret-key":
|
||
raise HTTPException(status_code=400, detail="X-Key 标头无效")
|
||
return x_key
|
||
```
|
||
|
||
全局依赖项很有用，后面的安全性就可以使用全局依赖项
|
||
|
||
```python
|
||
app = FastAPI(
|
||
dependencies=[Depends(verify_token), Depends(verify_key)]
|
||
)
|
||
|
||
@app.get("/items/")
|
||
async def read_items():
|
||
return [{"item": "Portal Gun"}, {"item": "Plumbus"}]
|
||
|
||
@app.get("/users/")
|
||
async def read_users():
|
||
return [{"username": "Rick"}, {"username": "Morty"}]
|
||
```
|
||
|
||
安全性
|
||
---
|
||
|
||
待更新
|
||
|
||
参考
|
||
---
|
||
|
||
- [Python 备忘清单](./python.md) _(jaywcjlove.github.io)_
|
||
- [FastAPI 官方文档](https://fastapi.tiangolo.com/zh/tutorial/) _(fastapi.tiangolo.com)_
|