Automatically clean up "Previous Mobile Applications"

-June 27, 2015 -

iTunes keeps a "Previous Mobile Applications" folder of questionable value, which always annoys me. It eats into disk space and wastes syncing/backup cycles and bandwidth; you can easily find horror stories online about 100GB+ PMA folders. The value? You might be able to roll back to an earlier version, or restore an app pulled from the App Store. Really? I never had that need in my life¹; have you? Worst of all, there should be a periodic clean up option — just like how deleted mail are automatically purged after one month, but the option is missing.

Therefore, I wrote a trivial Python script to do the periodic cleanup. Feel free to grab my script below (also available at http://git.io/previous-mobile-applications) to save a few minutes of hacking. It should be plugged into a daily or weekly or monthly cron job (or the equivalent), and it writes data to ~/.local/share/itunes/previous-mobile-applications.json by default. To customize, just modify the global constants.

#!/usr/bin/env python3
-
-"""Periodically clean up "Previous Mobile Applications" of iTunes."""
-
-import arrow
-import datetime
-import json
-import os
-import sys
-
-OFFENDING_DIR = os.path.expanduser("~/Music/iTunes/iTunes Media/Mobile Applications/Previous Mobile Applications")
-STORAGE_DIR = os.path.expanduser("~/.local/share/itunes")
-STORAGE_FILE = os.path.join(STORAGE_DIR, "previous-mobile-applications.json")
-
-DELETE_AFTER = datetime.timedelta(days=7)
-
-def load_storage():
-    """Load stored dictionary of seen apps from STORAGE_FILE.
-
-    Returns
-    -------
-    seen_app_dict : dict
-        Dictionary of (app_filename, first_seen_date) key-value pairs,
-        where app_filename is str, and last_seen_date is datetime.date.
-
-    """
-    os.makedirs(STORAGE_DIR, mode=0o700, exist_ok=True)
-    try:
-        with open(STORAGE_FILE, encoding="utf-8") as fp:
-            serializable_seen_app_dict = json.load(fp)
-            return {app_filename: arrow.get(serialized_first_seen_date).date()
-                    for app_filename, serialized_first_seen_date in serializable_seen_app_dict.items()}
-    except OSError:
-        return {}
-
-def write_storage(seen_app_dict):
-    """Write the dictionary of seen apps to STORAGE_FILE.
-
-    Parameters
-    ----------
-    seen_app_dict : dict
-        See the return format of load_storage().
-
-    Returns
-    -------
-    0 or 1
-        Return code indicating success or failure.
-
-    """
-    # convert datetime.time to str (ISO 8601)
-    serializable_seen_app_dict = {app_filename: first_seen_date.isoformat()
-                                  for app_filename, first_seen_date in seen_app_dict.items()}
-    os.makedirs(STORAGE_DIR, mode=0o700, exist_ok=True)
-    try:
-        with open(STORAGE_FILE, mode="w", encoding="utf-8") as fp:
-            json.dump(serializable_seen_app_dict, fp, indent=2, sort_keys=True)
-        return 0
-    except OSError as err:
-        sys.stderr.write("error: failed to write to '%s': %s" % (STORAGE_FILE, str(err)))
-        return 1
-
-def main():
-    """Main.
-
-    Returns
-    -------
-    0 or 1
-        Return code indicating success or failure.
-
-    """
-    if not os.path.isdir(OFFENDING_DIR):
-        # good, you don't have that junk
-        return 0
-
-    today = datetime.date.today()
-    seen_app_dict = load_storage()
-    current_app_list = os.listdir(OFFENDING_DIR)
-
-    # boot already disappeared apps
-    for app in [app for app in seen_app_dict if app not in current_app_list]:
-        seen_app_dict.pop(app)
-
-    # add newly appeared apps
-    for app in [app for app in current_app_list if app not in seen_app_dict]:
-        seen_app_dict[app] = today
-
-    # delete expired apps
-    returncode = 0
-    newly_deleted_apps = []
-    for app in seen_app_dict:
-        if today >= seen_app_dict[app] + DELETE_AFTER:
-            app_path = os.path.join(OFFENDING_DIR, app)
-            try:
-                os.remove(app_path)
-                newly_deleted_apps.append(app)
-            except OSError as err:
-                sys.stderr.write("error: failed to remove '%s': %s" % (app_path, str(err)))
-                returncode = 1
-
-    for app in newly_deleted_apps:
-        seen_app_dict.pop(app)
-
-    # write data to disk
-    returncode |= write_storage(seen_app_dict)
-
-    return returncode
-
-if __name__ == "__main__":
-    exit(main())

Full disclosure: unlike many people, I'm not very obsessed with my phone, and I only have about two dozen third-party apps.↩︎