Django 异步生成器通过流式响应TypeError: ‘async_generator‘ object is not iterable

Django 异步生成器通过流式响应，本篇文章已解决

djagno项目的StreamingHttpResponse只支持响应迭代器，不支持异步生成器的方式去响应数据

默认情况会报错 TypeError: ‘async_generator‘ object is not iterable

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/django/core/handlers/base.py", line 231, in _get_response_async
    response = await wrapped_callback(request, *callback_args, **callback_kwargs)
=
  File "/usr/local/lib/python3.7/site-packages/django/http/response.py", line 386, in _set_streaming_content
    self._iterator = iter(value)
TypeError: 'async_generator' object is not iterable

解决方式：创建一个名为stream的装饰器，它可以与一个协程函数一起使用，使其与Django的StreamingHttpResponse兼容。
下面是一个例子：

1.url.py

# url
path('v1/index', index),  

2.view.py

import asyncio
import functools
from django.http import StreamingHttpResponse
def stream(coroutine_function):
    @functools.wraps(coroutine_function)
    def wrapper(*args, **kwargs):
        coroutine = coroutine_function(*args, **kwargs)
        try:
            while True:
                yield asyncio.run(coroutine.__anext__())
        except StopAsyncIteration:
            pass
    return wrapper
    
@stream
async def chunks():
    for char in 'Hello, world!':
        yield char
        await asyncio.sleep(1)
        
async def index(request):
    return StreamingHttpResponse(chunks())

3.安装 nest_asyncio

pip install nest_asyncio

4.在settings.py文件的顶部调用apply(), 添加以下代码

import nest_asyncio
nest_asyncio.apply()

5.接下来就是运行项目，调用接口，实现Django 异步生成器通过流式响应

至此，实现Django 异步生成器通过流式响应

如果需要对异步生成器的内容进行操作，可以以下实现

@stream
async def index():
    @stream
    async def chunks() -> iter:
            async for event in 返回异步生成器方法:
            	yield event
            	
    for i in chunks():
    	# 对chunk进行操作
        print(i)
        yield i

def index(request):
    return StreamingHttpResponse(index())