update from Atlas

futures/countries/flags3_threadpool.py

@@ -0,0 +1,77 @@
+"""Download flags of top 10 countries by population
+
+ThreadPool version
+
+Sample run::
+
+    $ python3 pop10_threadpool1.py
+    BR retrieved.
+    PK retrieved.
+    BD retrieved.
+    JP retrieved.
+    CN retrieved.
+    IN retrieved.
+    RU retrieved.
+    NG retrieved.
+    US retrieved.
+    ID retrieved.
+    10 flags downloaded in 0.63s
+
+"""
+
+from concurrent import futures
+from collections import namedtuple
+from enum import Enum
+
+import requests
+
+from flags_sequential2 import BASE_URL
+from flags_sequential2 import save_flag, get_flag, main, Counts
+
+MAX_WORKERS = 200
+
+Status = Enum('Status', 'ok not_found error')
+Result = namedtuple('Result', 'status data')
+
+
+def get_country(cc):
+    url = '{}/{cc}/metadata.json'.format(BASE_URL, cc=cc.lower())
+    res = requests.get(url)
+    if res.status_code != 200:
+        res.raise_for_status()
+    return res.json()['country']
+
+
+def download_one(cc):
+    try:
+        image = get_flag(cc)
+        country = get_country(cc)
+    except requests.exceptions.HTTPError as exc:
+        res = exc.response
+        if res.status_code == 404:
+            status = Status.not_found
+        else:
+            msg = '{} failed: {res.status_code} - {res.reason}'
+            print(msg.format(cc, res=exc.response))
+            status = Status.error
+    else:
+        print('{} retrieved.'.format(cc))
+        country = country.replace(' ', '_')
+        save_flag(image, '{}-{}.gif'.format(country, cc))
+        status = Status.ok
+    return Result(status, cc)
+
+
+def download_many(cc_list):
+    workers = min(len(cc_list), MAX_WORKERS)
+    with futures.ThreadPoolExecutor(workers) as executor:
+        res = executor.map(download_one, sorted(cc_list))
+    res = list(res)
+    counts = []
+    for status in Status:
+        counts.append(len([r for r in res if r.status == status]))
+    return Counts(*counts)
+
+
+if __name__ == '__main__':
+    main(download_many)