For syncing music to a MP3 player from clementine

sync_to_player.py

#!/usr/bin/env python

import hashlib
import os
import os.path
import shutil
import sys
import urllib

import sqlite3
import os.path

OUT_DIR = "/media/usb/MUSIC"
PLS = "Mix"
DB_PATH = "/home/christopher/.config/Clementine/clementine.db"

query = """
  SELECT songs.filename FROM playlist_items
     JOIN songs, playlists
     ON songs.rowid = playlist_items.library_id AND playlists.rowid = playlist_items.playlist
     WHERE playlists.name = ?
"""

conn = sqlite3.connect(DB_PATH)
cursor = conn.cursor()

if len(sys.argv) > 1:
    PLS = sys.argv[1]

cursor.execute(query, (PLS,))
files = [urllib.unquote(str(fn)).replace("file://", "") for (fn,) in cursor]
conn.close()

if len(files) == 0:
    sys.stderr.write("No such playlist or playlist empty\n")
    sys.exit(1)

checksum_cache = "sync_cache_%s.txt" % (PLS,)

try:
    f = open(checksum_cache)
    cache = [l.strip().split(" ", 1) for l in f.readlines()]
    cache = [(fn, csum) for csum, fn in cache]
    cache = dict(cache)
    f.close()
except IOError:
    cache = dict()

def compute_digest(filename):
    csum = hashlib.md5()
    f = open(filename)
    while True:
        data = f.read(csum.block_size)
        if not data:
            break
        csum.update(data)
    return csum.hexdigest()

try:
    checksums = []

    for i, f in enumerate(files):
        sys.stdout.write("\rCompute checksums... %4d/%d  %d%%" % (i, len(files), int((float(i)/len(files)) * 100)))
        sys.stdout.flush()
        
        if f in cache:
            checksums.append((f, cache[f]))
        else:
            digest = compute_digest(f) + ".mp3"
            checksums.append((f, digest))
            cache[f] = digest
    print "\rCompute checksums... done.                    "
finally:
    f = open(checksum_cache, "w")
    f.write("\n".join(["%s %s" % (csum, fn) for fn, csum in cache.items()]) + "\n")
    f.close()

if not os.path.exists(OUT_DIR):
    sys.stderr.write("Out directory does not exist. Is the device mounted?\n")
    sys.exit(1)

existing_files = set([f for f in os.listdir(OUT_DIR) if f.endswith(".mp3")])

to_add = [(f, csum) for (f, csum) in checksums if csum not in existing_files]
to_remove = existing_files - set([csum for f, csum in checksums])

prompt = ""

if to_add and to_remove:
    prompt = "Adding %d files and removing %d files. Proceed? [yN] " % (len(to_add), len(to_remove))
elif to_add:
    prompt = "Adding %d files. Proceed? [yN] " % (len(to_add),)
elif to_remove:
    prompt = "Removing %d files. Proceed? [yN] " % (len(to_remove),)

if prompt and raw_input(prompt) != "y":
    sys.stderr.write("Quiting.\n")
    sys.exit(1)

if to_add:
    i = 1
    for f, csum in to_add:
        sys.stdout.write("\rCopying... %4d/%d  %d%%" % (i, len(to_add), int((float(i)/len(to_add))*100)))
        sys.stdout.flush()
        
        dst = os.path.join(OUT_DIR, csum)
        try:
            shutil.copy(f, dst)
        except:
            os.remove(dst)
            raise
        i += 1
    print "\rCopying... done.             "

if to_remove:
    print "Removing %d files" % (len(to_remove),)
    for f in to_remove:
        os.remove(os.path.join(OUT_DIR, f))