copying text tags between mp3 files using id3v2 as a back-end.

id3copy.py

#!/usr/bin/env python
"""id3copy - copy id3 (text) tags from mp3 file SRC to mp3 file DEST

usage: id3copy [-h] [-v... | -q] SRC DEST

options:
  -h, --help  		show this help message and exit

  -v, --verbose		verbose output (give it twice for debug output)
  -q, --quiet           no information output

note 1:  
  this tool uses the program `id3v2` to read and then write the tags. it got
  developed, because the `id3cp` program adds wrong characters into the text
  tags.

note 2:
  this tool writes only TEXT tags (no images, etc). therefore use `id3cp'
  first and then correct the text tags with this tool.

"""

import os
import sys
import docopt
import atexit
import subprocess

def exename():
    exepath=sys.argv[0]
    pathparts=exepath.split(os.sep)
    return pathparts[-1]

args = {}

def get_tagtext(src):
    tagtext = subprocess.check_output(['id3v2', '-l', src], universal_newlines=True, stderr=subprocess.STDOUT)
    print_verbose("tagtext:\n%s" % tagtext)
    return tagtext

# List of allow keys
ALLOWEDKEYS = ['IPLS', 'LINK', 'SYLT', 'TALB', 'TBPM', 'TCOM', 'TCOP', 'TDAT', 'TDLY', 'TENC', 'TEXT', 'TIME', 'TIT2', 'TIT3', 'TKEY', 'TLAN', 'TOAL', 'TOFN', 'TOLY', 'TOPE', 'TORY', 'TOWN', 'TPE1', 'TPE2', 'TPE3', 'TPE4', 'TPUB', 'TRCK', 'TRDA', 'TRSN', 'TRSO', 'TSSE', 'TXXX', 'TYER', 'USER', 'USLT', 'WCOM', 'WCOP', 'WOAF', 'WOAR', 'WOAS', 'WORS', 'WPUB', 'WXXX']
# Seperator of comment from real value
INVALUESEP = ": "

def get_tagdict(tagtext):

    tagdict = {}
    pre=True
    
    try :
        for line in tagtext.splitlines():
            if pre:
                if line.find("id3v2 tag info for")>=0:
                    pre=False
            else:
                (k, v) = line.split(" ", 1)
                if k in ALLOWEDKEYS:
                    
                    i = v.find(INVALUESEP)
                    if i >= 0:
                        v =  v[i+len(INVALUESEP):]
                    print_verbose("keep frame '%s' with value '%s'" % (k,v))
                    tagdict[k]=v
                else:
                    print_verbose("cannot copy frame '%s'" % k)

    except ValueError, e:
        raise ValueError("cannot read id3 information properly")
        
    if pre==True:
        # raise exception if no id3(v2) information found (either no present or fopen error or... )
        raise ValueError("no id3 information found")
    
    print_verbose (tagdict)
    return tagdict

def apply_tagdict(dest, tagdict):
    for k in tagdict:
        v = tagdict[k]
        print_verbose("write frame '%s' with value '%s'" % (k, v))
        tagtext = subprocess.check_call(['id3v2', '--%s' %  k, v, dest], stderr=subprocess.STDOUT)


def work():
    src = args['SRC']
    dest = args['DEST']

    tagtext = get_tagtext(src)
    tagdict = get_tagdict(tagtext)
    apply_tagdict(dest, tagdict)

def print_verbose(msg):
    if args['--verbose']:
        print("--- %s" % str(msg))

if __name__ == '__main__':
    try:
        args = docopt.docopt(__doc__, version='0.1.0')
        print_verbose("args:\n%s" % str(args))
        work()

    except docopt.DocoptExit as e:

        print ("%s: wrong commandline" % exename())
        print (str(e))
        print ("try '%s -h' for more information." % exename())