refactor: replace string concatenations with f-strings

1 files changed, 20 insertions, 21 deletions

diff --git a/youtube/subscriptions.py b/youtube/subscriptions.py
index dafea58..7d3efab 100644
--- a/youtube/subscriptions.py
+++ b/youtube/subscriptions.py
@@ -126,7 +126,7 @@ def delete_thumbnails(to_delete):
                 os.remove(os.path.join(thumbnails_directory, thumbnail))
                 existing_thumbnails.remove(video_id)
         except Exception:
-            print('Failed to delete thumbnail: ' + thumbnail)
+            print(f'Failed to delete thumbnail: {thumbnail}')
             traceback.print_exc()
 
 
@@ -184,7 +184,7 @@ def _get_videos(cursor, number_per_page, offset, tag=None):
             'time_published': exact_timestamp(db_video[3]) if db_video[4] else posix_to_dumbed_down(db_video[3]),
             'author':   db_video[5],
             'author_id': db_video[6],
-            'author_url': '/https://www.youtube.com/channel/' + db_video[6],
+            'author_url': f'/https://www.youtube.com/channel/{db_video[6]}',
         })
 
     return videos, pseudo_number_of_videos
@@ -304,9 +304,9 @@ def posix_to_dumbed_down(posix_time):
         if delta >= unit_time:
             quantifier = round(delta/unit_time)
             if quantifier == 1:
-                return '1 ' + unit_name + ' ago'
+                return f'1 {unit_name} ago'
             else:
-                return str(quantifier) + ' ' + unit_name + 's ago'
+                return f'{quantifier} {unit_name}s ago'
     else:
         raise Exception()
 
@@ -363,7 +363,7 @@ def autocheck_dispatcher():
             time_until_earliest_job = earliest_job['next_check_time'] - time.time()
 
             if time_until_earliest_job <= -5:   # should not happen unless we're running extremely slow
-                print('ERROR: autocheck_dispatcher got job scheduled in the past, skipping and rescheduling: ' + earliest_job['channel_id'] + ', ' + earliest_job['channel_name'] + ', ' + str(earliest_job['next_check_time']))
+                print(f'ERROR: autocheck_dispatcher got job scheduled in the past, skipping and rescheduling: {earliest_job["channel_id"]}, {earliest_job["channel_name"]}, {earliest_job["next_check_time"]}')
                 next_check_time = time.time() + 3600*secrets.randbelow(60)/60
                 with_open_db(_schedule_checking, earliest_job['channel_id'], next_check_time)
                 autocheck_jobs[earliest_job_index]['next_check_time'] = next_check_time
@@ -451,7 +451,7 @@ def check_channels_if_necessary(channel_ids):
 
 
 def _get_atoma_feed(channel_id):
-    url = 'https://www.youtube.com/feeds/videos.xml?channel_id=' + channel_id
+    url = f'https://www.youtube.com/feeds/videos.xml?channel_id={channel_id}'
     try:
         return util.fetch_url(url).decode('utf-8')
     except util.FetchError as e:
@@ -485,16 +485,15 @@ def _get_channel_videos_first_page(channel_id, channel_status_name):
         return channel_info
     except util.FetchError as e:
         if e.code == '429' and settings.route_tor:
-            error_message = ('Error checking channel ' + channel_status_name
-                + ': YouTube blocked the request because the'
-                + ' Tor exit node is overutilized. Try getting a new exit node'
-                + ' by using the New Identity button in the Tor Browser.')
+            error_message = (f'Error checking channel {channel_status_name}: '
+                f'YouTube blocked the request because the Tor exit node is overutilized. '
+                f'Try getting a new exit node by using the New Identity button in the Tor Browser.')
             if e.ip:
-                error_message += ' Exit node IP address: ' + e.ip
+                error_message += f' Exit node IP address: {e.ip}'
             print(error_message)
             return None
         elif e.code == '502':
-            print('Error checking channel', channel_status_name + ':', str(e))
+            print(f'Error checking channel {channel_status_name}: {e}')
             return None
         raise
 
@@ -505,7 +504,7 @@ def _get_upstream_videos(channel_id):
     except KeyError:
         channel_status_name = channel_id
 
-    print("Checking channel: " + channel_status_name)
+    print(f"Checking channel: {channel_status_name}")
 
     tasks = (
         # channel page, need for video duration
@@ -550,15 +549,15 @@ def _get_upstream_videos(channel_id):
             times_published[video_id_element.text] = time_published
 
     except ValueError:
-        print('Failed to read atoma feed for ' + channel_status_name)
+        print(f'Failed to read atoma feed for {channel_status_name}')
         traceback.print_exc()
     except defusedxml.ElementTree.ParseError:
-        print('Failed to read atoma feed for ' + channel_status_name)
+        print(f'Failed to read atoma feed for {channel_status_name}')
 
     if channel_info is None: # there was an error
         return
     if channel_info['error']:
-        print('Error checking channel ' + channel_status_name + ': ' + channel_info['error'])
+        print(f'Error checking channel {channel_status_name}: {channel_info["error"]}')
         return
 
     videos = channel_info['items']
@@ -1023,7 +1022,7 @@ def get_subscriptions_page():
             tag = request.args.get('tag', None)
             videos, number_of_videos_in_db = _get_videos(cursor, 60, (page - 1)*60, tag)
             for video in videos:
-                video['thumbnail'] = util.URL_ORIGIN + '/data/subscription_thumbnails/' + video['id'] + '.jpg'
+                video['thumbnail'] = f'{util.URL_ORIGIN}/data/subscription_thumbnails/{video["id"]}.jpg'
                 video['type'] = 'video'
                 video['item_size'] = 'small'
                 util.add_extra_html_info(video)
@@ -1033,7 +1032,7 @@ def get_subscriptions_page():
             subscription_list = []
             for channel_name, channel_id, muted in _get_subscribed_channels(cursor):
                 subscription_list.append({
-                    'channel_url': util.URL_ORIGIN + '/channel/' + channel_id,
+                    'channel_url': f'{util.URL_ORIGIN}/channel/{channel_id}',
                     'channel_name': channel_name,
                     'channel_id': channel_id,
                     'muted': muted,
@@ -1109,17 +1108,17 @@ def serve_subscription_thumbnail(thumbnail):
     for quality in ('hq720.jpg', 'sddefault.jpg', 'hqdefault.jpg'):
         url = f"https://i.ytimg.com/vi/{video_id}/{quality}"
         try:
-            image = util.fetch_url(url, report_text="Saved thumbnail: " + video_id)
+            image = util.fetch_url(url, report_text=f"Saved thumbnail: {video_id}")
             break
         except util.FetchError as e:
             if '404' in str(e):
                 continue
-            print("Failed to download thumbnail for " + video_id + ": " + str(e))
+            print(f"Failed to download thumbnail for {video_id}: {e}")
             flask.abort(500)
         except urllib.error.HTTPError as e:
             if e.code == 404:
                 continue
-            print("Failed to download thumbnail for " + video_id + ": " + str(e))
+            print(f"Failed to download thumbnail for {video_id}: {e}")
             flask.abort(e.code)
 
     if image is None: