final concurrency examples

futures/countries/flags2_sequential.py

@@ -4,71 +4,84 @@ Sequential version
 
 Sample run::
 
-    $
+    $ python3 flags2_sequential.py -s DELAY b
+    DELAY site: http://localhost:8002/flags
+    Searching for 26 flags: from BA to BZ
+    1 concurrent connection will be used.
+    --------------------
+    17 flags downloaded.
+    9 not found.
+    Elapsed time: 13.36s
 
 """
 
+import collections
+
 import requests
 import tqdm
 
-from flag_utils import main, save_flag, Counts, Status, Result
+from flags2_common import main, save_flag, HTTPStatus, Result
 
 
 DEFAULT_CONCUR_REQ = 1
 MAX_CONCUR_REQ = 1
 
-
+# BEGIN FLAGS2_BASIC_HTTP_FUNCTIONS
 def get_flag(base_url, cc):
     url = '{}/{cc}/{cc}.gif'.format(base_url, cc=cc.lower())
-    res = requests.get(url)
-    if res.status_code != 200:
-        res.raise_for_status()
-    return res.content
+    resp = requests.get(url)
+    if resp.status_code != 200:  # <1>
+        resp.raise_for_status()
+    return resp.content
 
 
 def download_one(cc, base_url, verbose=False):
     try:
         image = get_flag(base_url, cc)
-    except requests.exceptions.HTTPError as exc:
+    except requests.exceptions.HTTPError as exc:  # <2>
         res = exc.response
         if res.status_code == 404:
-            status = Status.not_found
-            msg = ''
-        else:
-            status = Status.error
-            msg = 'error {res.status_code} - {res.reason}'
-            msg = msg.format(res=exc.response)
-    except requests.exceptions.ConnectionError as exc:
-        status = Status.error
-        msg = 'failed: {}'.format(cc, exc.args)
+            status = HTTPStatus.not_found  # <3>
+            msg = 'not found'
+        else:  # <4>
+            raise
     else:
         save_flag(image, cc.lower() + '.gif')
-        status = Status.ok
+        status = HTTPStatus.ok
         msg = 'OK'
 
-    if verbose and msg:
+    if verbose:  # <5>
         print(cc, msg)
 
-    return Result(status, cc)
-
+    return Result(status, cc)  # <6>
+# END FLAGS2_BASIC_HTTP_FUNCTIONS
 
+# BEGIN FLAGS2_DOWNLOAD_MANY_SEQUENTIAL
 def download_many(cc_list, base_url, verbose, max_req):
-    counts = [0, 0, 0]
+    counter = collections.Counter()  # <1>
+    cc_iter = sorted(cc_list)  # <2>
     if not verbose:
-        cc_iter = tqdm.tqdm(sorted(cc_list))
-    else:
-        cc_iter = sorted(cc_list)
-    for cc in cc_iter:
+        cc_iter = tqdm.tqdm(cc_iter)  # <3>
+    for cc in cc_iter:  # <4>
         try:
-            res = download_one(cc, base_url, verbose)
-        except Exception as exc:
-            msg = 'Unexpected exception for {}: {!r}'
-            print(msg.format(cc, exc))
-        else:
-            counts[res.status.value-1] += 1
+            res = download_one(cc, base_url, verbose)  # <5>
+        except requests.exceptions.HTTPError as exc:  # <6>
+            error_msg = 'HTTP error {res.status_code} - {res.reason}'
+            error_msg = error_msg.format(res=exc.response)
+        except requests.exceptions.ConnectionError as exc:  # <7>
+            error_msg = 'Connection error'
+        else:  # <8>
+            error_msg = ''
+            status = res.status
 
-    return Counts(*counts)
+        if error_msg:
+            status = HTTPStatus.error  # <9>
+        counter[status] += 1  # <10>
+        if verbose and error_msg: # <11>
+            print('*** Error for {}: {}'.format(cc, error_msg))
 
+    return counter  # <12>
+# END FLAGS2_DOWNLOAD_MANY_SEQUENTIAL
 
 if __name__ == '__main__':
     main(download_many, DEFAULT_CONCUR_REQ, MAX_CONCUR_REQ)