https://lolicon.app

loli-dl.py

# /// script
# requires-python = ">=3.14"
# dependencies = [
#     "aiofiles>=25.1.0",
#     "httpx[http2]>=0.28.1",
# ]
# ///

import asyncio
import sys

from pathlib import PurePath
from signal import SIGINT

import aiofiles
import httpx

MAX_QUEUE_SIZE = 60
MAX_WORKERS = 10

stop_now = asyncio.Event()

async def download(client: httpx.AsyncClient, queue: asyncio.Queue):
    while True:
        if stop_now.is_set():
            break
        url, path = await queue.get()
    
        async with (
            aiofiles.open(path, 'wb') as output,
            client.stream('GET', url) as r
        ):
            if r.status_code != 200:
                print(f"{url} not found on Pixiv, ignoring", file=sys.stderr)

            if size := r.headers.get('Content-Length'):
                await output.truncate(int(size))
        
            async for chunk in r.aiter_bytes():
                await output.write(chunk)

            if size:
                print(f"Downloaded {url} -> {path}; content-length {size}")
            else:
                print(f"Downloaded {url} -> {path}; content-length unknown")


async def main():
    loop = asyncio.get_event_loop()
    loop.add_signal_handler(SIGINT, lambda: stop_now.set())

    async with (
        httpx.AsyncClient(http2=True, timeout=None) as client,
    ):
        queue = asyncio.Queue(MAX_QUEUE_SIZE)
        tasks = set()

        # Shielding is required to prevent premature writes.
        for _ in range(MAX_WORKERS):
            tasks.add(asyncio.shield(download(client, queue)))

        while True:
            if stop_now.is_set():
                break
            
            r = await client.get('https://api.lolicon.app/setu/v2?num=20')

            if r.status_code != 200:
                print(f"Lolicon API returned {r.status_code}", file=sys.stderr)
                continue

            data = r.json()['data']
            for entry in data:
                url = httpx.URL(entry['urls']['original'])
                filename = PurePath(url.path).name

                await queue.put((url, filename))
            await asyncio.sleep(5)

        await asyncio.gather(*tasks)
            
if __name__ == '__main__':
    asyncio.run(main())

All it takes to run is

$ uv run https://gist.githubusercontent.com/cynthia2006/0c6e0e72786ba6a6e5aa655c50ac3eb3/raw/19f6b4c93997d7f502c56649417c46a16b5dab55/loli-dl.py