update from Atlas with major reorg

attic/concurrency/wikipedia/daypicts_asyncio.py

@@ -0,0 +1,62 @@
+"""
+Wikipedia Picture of the Day (POTD) download example
+"""
+
+import sys
+import asyncio
+import aiohttp
+
+from daypicts import main, NoPictureForDate
+from daypicts import POTD_BASE_URL, POTD_IMAGE_RE
+
+GLOBAL_TIMEOUT = 300  # seconds
+MAX_CONCURRENT_REQUESTS = 30
+
+
+@asyncio.coroutine
+def get_picture_url(iso_date, semaphore):
+    page_url = POTD_BASE_URL+iso_date
+    with (yield from semaphore):
+        response = yield from aiohttp.request('GET', page_url)
+        text = yield from response.text()
+    pict_url = POTD_IMAGE_RE.search(text)
+    if pict_url is None:
+        raise NoPictureForDate(iso_date)
+    return 'http:' + pict_url.group(1)
+
+
+@asyncio.coroutine
+def get_picture_urls(dates, verbose=False):
+    semaphore = asyncio.Semaphore(MAX_CONCURRENT_REQUESTS)
+    tasks = [get_picture_url(date, semaphore) for date in dates]
+    urls = []
+    count = 0
+    # get results as jobs are done
+    for job in asyncio.as_completed(tasks, timeout=GLOBAL_TIMEOUT):
+        try:
+            url = yield from job
+        except NoPictureForDate as exc:
+            if verbose:
+                print('*** {!r} ***'.format(exc))
+            continue
+        except aiohttp.ClientResponseError as exc:
+            print('****** {!r} ******'.format(exc))
+            continue
+        count += 1
+        if verbose:
+            print(format(count, '3d'), end=' ')
+            print(url.split('/')[-1])
+        else:
+            print(url)
+        urls.append(url)
+    return urls
+
+
+def run_loop(dates, verbose=False):
+
+    loop = asyncio.get_event_loop()
+    return loop.run_until_complete(get_picture_urls(dates, verbose))
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:], run_loop)