use the standard logging module & refactoring

Including more command line parameters & better usage messages.

1 files changed, 12 insertions, 8 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))