update from Atlas

futures/countries/flags_asyncio2.py

@@ -0,0 +1,61 @@
+"""Download flags of top 20 countries by population
+
+asyncio+aiottp version
+
+Sample run::
+
+    $ python3 flags_asyncio.py
+    NG retrieved.
+    FR retrieved.
+    IN retrieved.
+    ...
+    EG retrieved.
+    DE retrieved.
+    IR retrieved.
+    20 flags downloaded in 1.08s
+
+"""
+
+import asyncio
+
+import aiohttp
+
+from flags import BASE_URL, save_flag, main
+
+
+@asyncio.coroutine
+def get_flag(cc):
+    url = '{}/{cc}/{cc}.gif'.format(BASE_URL, cc=cc.lower())
+    res = yield from aiohttp.request('GET', url)
+    image = yield from res.read()
+    return image
+
+
+@asyncio.coroutine
+def download_one(cc):
+    image = yield from get_flag(cc)
+    print('{} retrieved.'.format(cc))
+    save_flag(image, cc.lower() + '.gif')
+    return cc
+
+
+@asyncio.coroutine
+def downloader_coro(cc_list):
+    to_do = [download_one(cc) for cc in cc_list]
+    results = []
+    for future in asyncio.as_completed(to_do):
+        print(future)
+        result = yield from future
+        results.append(result)
+    return results
+
+
+def download_many(cc_list):
+    loop = asyncio.get_event_loop()
+    results = loop.run_until_complete(downloader_coro(cc_list))
+    loop.close()
+    return len(results)
+
+
+if __name__ == '__main__':
+    main(download_many)