本文實例講述了Sanic框架流式傳輸操作。分享給大家供大家參考，具體如下：

簡介

Sanic是一個類似Flask的Python 3.5+ Web服務(wù)器，它的寫入速度非常快。除了Flask之外，Sanic還支持異步請求處理程序。這意味著你可以使用Python 3.5中新的閃亮的異步/等待語法，使你的代碼非阻塞和快速。

在前面一篇《Sanic框架Cookies操作》中已經(jīng)講到，如何在Sanic中使用Cookie，接下來將介紹一下Sanic的流的使用：

請求流式傳輸

Sanic允許通過流獲取請求數(shù)據(jù)，如下所示，當請求結(jié)束時，request.stream.get()返回為None，只有post、put和patch decorator擁有流參數(shù)：

from sanic.response import stream@app.post("/post_stream",stream=True)async def post_stream(request):  async def streaming(response):    while True:      body = await request.stream.get()      if body is None:        break      body = body.decode("utf-8")      reponse.write(body)  return stream(streaming)@app.put("/put_stream",stream=True)async def put_stream(request):  async def streaming(response):    while True:      body = await request.stream.get()      if body is None:        break      body = body.decode("utf-8")      response.write("utf-8")  return stream(streaming)

除了上述例子的方法之外，我們之前還講過用add_route方法動態(tài)添加路由：

from sanic.response import textfrom sanic.views import HTTPMethodViewfrom sanic.views import stream as stream_decoratorclass StreamView(HTTPMethodView)  @stream_decorator  async def post(self,request)    result = ''    while True:      body = await request.stream.get()      if body is None:        break      body = body.decode('utf-8')      result += body    return text(result)app.add_route(StreamView.as_view(),"/method_view")

值得注意的是，stream_decorator裝飾器中處理函數(shù)的函數(shù)名稱，若為post則為post請求，若為put則為put請求。在之前講述路由的文章《Sanic框架路由用法》中講到一個CompositionView類來自定義一個路由，CompositionView在流式請求中同樣適用:

from sanic.views import CompositionViewasync def post_stream_view(request):  result = ''  while True:    body = await request.stream.get()    if body is None:      break    body = body.decode('utf-8')    result += body  return text(result)view = CompositionView()view.add(['POST'],post_stream_view,stream=True)app.add_route(view,"/post_stream_view")

響應(yīng)流式傳輸

Sanic允許你使用stream方法將內(nèi)容傳輸?shù)娇蛻舳耍摲椒ń邮芤粋€通過StreamingHTTPResponse傳入的對象的協(xié)程回調(diào)，舉個栗子：

from sanic.response import stream@app.route("/post_stream_info",methods=["POST"])async def post_stream_info(request):  async def streaming(response):    response.write("no")    response.write("bug")  return stream(streaming)