add file upload for fastapi

_drafts/2024-02-18-pydantic.md

@@ -293,13 +293,17 @@ print(mod.code)
 
 ```python
 # server.py
-from typing import Union, Annotated
-from fastapi import FastAPI, Query, Path
-import uvicorn
-from pydantic import BaseModel, Field
+from fastapi import FastAPI
+from fastapi import File, UploadFile   # 
+from fastapi import Form               # 表单
+from fastapi import Path, Query, Body  # 分别对应 HTTP 协议的路径, 请求参数, 请求体
+from pydantic import Field
+from typing import List, Annotated, Union
 
 app = FastAPI()
 
+
+# 1. path parameter and query parameter
 # http://<host>:<port>/items/a/b/?q=asd
 # p 是路径参数 (path parameter), q 是查询参数 (query parameter)
 # {"p": 123, "q": "asd"}, 注意这里限制了 p 是整数, 因此会自动进行校验并转换
@@ -312,11 +316,37 @@ async def read_items(
         "p": p,
         "desc": desc,
     }
+
+# 2.1 单文件上传
+@app.post("/upload/")
+async def create_upload_file(
+    file: UploadFile = File(...),
+    a: str = Form(...),
+):
+    name = file.filename
+    file_content = await file.read()
+    sha256_hash = hashlib.sha256(file_content).hexdigest()
+    return {"hash": sha256_hash, "name": name}
+
+# 2. 多文件上传
+@app.post("/uploads/")
+async def create_upload_file(
+    file: List[UploadFile] = File(...),
+    a: str = Form(...),
+):
+    file = file[0]
+    name = file.filename
+    file_content = await file.read()
+    sha256_hash = hashlib.sha256(file_content).hexdigest()
+    return {"hash": sha256_hash, "name": name}
+
 uvicorn.run(app, host="127.0.0.1", port=8000)
 ```
 
 ```python
 # client.py
 import requests
 requests.get("http://localhost/items/123?desc=hello")
+requests.post("http://localhost/upload/", files=[('file', open(filename, 'rb'))], data={"a": "abc"})
+requests.post("http://localhost/uploads/", files=[('file', open(filename, 'rb'))], data={"a": "abc"})
 ```