work with generator source about ijson HOT 3 OPEN

@Bubu thanks for the very good question. I have pondered about this myself in the past, I have also thought it would be nice to have -- so having someone else express interest in the idea is definitely good.

I think this should be possible, but needs some care to great care. The ijson functions actually already support generators as inputs, but those are assumed to be the lower-level generator functions of ijson itself (e.g., you can use ijson.parse() as the input to ijson.items, see the "Intercepting events" section of the README). It should still be possible to detect those separately from any other arbitrary generators and act differently though. After that it should all work, because funnily enough we internally turn file objects into generators!

The C backend might need some more extra care as well.

I can't promise anything in terms of deadlines. But like I said, I'm onboard with the idea, and if someone decides to step in and give it a crack in the meanwhile I'll be happy to review code and PRs.

from ijson.

For those coming in the future: see #58 (comment) for an (untested, personally) example of a simple file-like wrapper around a generator as a workaround.

from ijson.

For those coming in the future: see #58 (comment) for an (untested, personally) example of a simple file-like wrapper around a generator as a workaround.

Based on the above, here is what I'm using with httpx:

import httpx
import ijson
from contextlib import asynccontextmanager
from typing import AsyncIterator

class HttpxStreamAsFile:
    def __init__(self, url: str):
        self.url = url
        self.data = None
        self.client = httpx.AsyncClient()

    @asynccontextmanager
    async def create_stream(self) -> AsyncIterator:
        try:
            await self._create_stream()
            yield
        finally:
            await self.client.aclose()

    async def _create_stream(self) -> None:
        req = self.client.build_request("GET", self.url)
        res = await self.client.send(req, stream=True)
        self.data = res.aiter_bytes()

    async def read(self, n: int) -> None:
        if self.data is None or n == 0:
            return b""

        return await anext(self.data, b"")


async def main():
    url = "your-url"
    httpx_as_file = HttpxStreamAsFile(
        url
    )
    async with httpx_as_file.create_stream():
        async for prefix, event, name in ijson.items(httpx_as_file):
            print(prefix, event, name)

from ijson.