use the standard logging module & refactoring

Including more command line parameters & better usage messages.

2 files changed, 65 insertions, 30 deletions

diff --git a/print_mutual_friends.py b/print_mutual_friends.py
index 6895a3c..b3beb39 100644
--- a/print_mutual_friends.py
+++ b/print_mutual_friends.py
@@ -8,26 +8,30 @@ def users_get(user_ids):
     response = api.users_get(user_ids=','.join(user_ids),
                              fields='screen_name')
     if len(response) < len(user_ids):
-        print('Error: couldn\'t find at least one of the users!',
-              file=sys.stderr)
-        sys.exit(1)
+        raise RuntimeError('Couldn\'t find at least one of the users!')
     return response
 
 def friends_get(user_id):
     return api.friends_get(user_id=user_id)
 
-def format_friend(user):
-    s = '{} {}'.format(user['last_name'], user['first_name'])
+def extract_screen_name_or_uid(user):
     if 'screen_name' in user:
-        s += ' ({})'.format(user['screen_name'])
-    return s
+        return user['screen_name']
+    return 'id' + str(user['uid'])
+
+def format_friend(user):
+    return '{} {} ({})'.format(
+        user['last_name'], user['first_name'],
+        extract_screen_name_or_uid(user))
 
 if __name__ == '__main__':
     import argparse
-    parser = argparse.ArgumentParser()
+    parser = argparse.ArgumentParser(
+        description='Learn who your ex and her new boyfriend are both friends with.')
     parser.add_argument(metavar='UID', dest='user_ids', nargs='+',
                         help='user IDs or "screen names"')
     args = parser.parse_args()
+
     users = users_get(args.user_ids)
     user_ids = map(lambda user: user['uid'], users)
     friend_lists = map(frozenset, map(friends_get, user_ids))
diff --git a/track_online.py b/track_online.py
index 7a4085d..ed43f11 100644
--- a/track_online.py
+++ b/track_online.py
@@ -2,7 +2,9 @@
 # This file is licensed under the terms of the MIT License.
 # See LICENSE.txt for details.
 
+import argparse
 from datetime import datetime
+import logging
 import time
 import sys
 
@@ -12,31 +14,26 @@ def users_get(user_ids):
     response = api.users_get(user_ids=','.join(user_ids),
                              fields='online,last_seen')
     if len(response) < len(user_ids):
-        print('Error: couldn\'t find at least one of the users!',
-              file=sys.stderr)
-        sys.exit(1)
+        raise RuntimeError('Couldn\'t update status of at least one of the users!')
     return response
 
-def log(s):
-    print('[{}] {}'.format(datetime.now().replace(microsecond=0), s))
-
 def format_user_name(user):
     return '{} {}'.format(user['last_name'], user['first_name'])
 
 def user_is_online(user):
-    log('{} is ONLINE'.format(format_user_name(user)))
+    logging.info('{} is ONLINE'.format(format_user_name(user)))
 
 def user_is_offline(user):
     user_name = format_user_name(user)
-    log('{} is OFFLINE'.format(user_name))
+    logging.info('{} is OFFLINE'.format(user_name))
     last_seen = datetime.fromtimestamp(user['last_seen']['time'])
-    log('{} was last seen at {}'.format(user_name, last_seen))
+    logging.info('{} was last seen at {}'.format(user_name, last_seen))
 
 def user_went_online(user):
-    log('{} went ONLINE'.format(format_user_name(user)))
+    logging.info('{} went ONLINE'.format(format_user_name(user)))
 
 def user_went_offline(user):
-    log('{} went OFFLINE'.format(format_user_name(user)))
+    logging.info('{} went OFFLINE'.format(format_user_name(user)))
 
 def print_user(status):
     if status['online']:
@@ -44,25 +41,59 @@ def print_user(status):
     else:
         user_is_offline(status)
 
-def print_user_update(status):
+def print_status_update(status):
     if status['online']:
         user_went_online(status)
     else:
         user_went_offline(status)
 
-if __name__ == '__main__':
-    import argparse
-    parser = argparse.ArgumentParser()
-    parser.add_argument(metavar='UID', dest='user_ids', nargs='+',
-                        help='user IDs or "screen names"')
-    args = parser.parse_args()
-    users = users_get(args.user_ids)
+def parse_timeout(source):
+    timeout = int(source)
+    if timeout < 1:
+        raise argparse.ArgumentTypeError(
+            'please specify a positive number of seconds as refresh timeout')
+    return timeout
+
+DEFAULT_TIMEOUT=5
+
+def print_initial_status(user_ids):
+    users = users_get(user_ids)
     for user in users:
         print_user(user)
+    return users
+
+def loop_update_status(users, user_ids, timeout=DEFAULT_TIMEOUT):
     while True:
-        time.sleep(5)
-        updated_users = users_get(args.user_ids)
+        time.sleep(timeout)
+        updated_users = users_get(user_ids)
         for i in range(len(updated_users)):
             if users[i]['online'] != updated_users[i]['online']:
                 users[i] = updated_users[i]
-                print_user_update(updated_users[i])
+                print_status_update(updated_users[i])
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(
+        description='Track when people go online/offline.')
+    parser.add_argument(metavar='UID', dest='user_ids', nargs='+',
+                        help='user IDs or "screen names"')
+    parser.add_argument('-t', '--timeout', default=DEFAULT_TIMEOUT,
+                        type=parse_timeout,
+                        help='set refresh interval (seconds)')
+    parser.add_argument('-l', '--log', type=argparse.FileType('w'),
+                        default=sys.stdout,
+                        help='set log file path (stdout by default)')
+    args = parser.parse_args()
+
+    logging.basicConfig(format='[%(asctime)s] %(message)s',
+                        stream=args.log,
+                        level=logging.INFO,
+                        datefmt='%Y-%m-%d %H:%M:%S')
+
+    try:
+        users = print_initial_status(args.user_ids)
+        loop_update_status(users, args.user_ids, timeout=args.timeout)
+    except KeyboardInterrupt:
+        pass
+    except Exception as e:
+        logging.exception(e)
+        sys.exit(1)