old gmusicapi code to do a generic metadata copy between audio files

gistfile1.py

import logging

import mutagen

log = logging.getLogger(__name__)


def copy_md_tags(from_fname, to_fname):
    """Copy all metadata from *from_fname* to *to_fname* and write.

    Return True on success, False if not all keys were copied/saved."""

    from_tags = mutagen.File(from_fname, easy=True)
    to_tags = mutagen.File(to_fname, easy=True)

    if from_tags is None or to_tags is None:
        log.debug("couldn't find an appropriate handler for tag files: '%s' '%s'",
                  from_fname, to_fname)
        return False

    success = True

    for k, v in from_tags.iteritems():
        try:
            #Some tags don't store values in strings, but in special container types.
            #Those should be converted to strings so we can safely save them.
            #Also, the value might be a list of tags or a single tag.

            if not isinstance(v, basestring):
                safe = [str(e) for e in v]
            else:
                safe = str(e)

            to_tags[k] = safe
        except mutagen.easyid3.EasyID3KeyError:
            #Raised because we're copying in an unsupported in easy-mode key.
            log.debug("skipping non easy key", exc_info=True)
        except:
            #lots of things can go wrong, just skip the key
            log.warning("problem when copying keys from '%s' to '%s'",
                        from_fname, to_fname, exc_info=True)
            success = False

    try:
        to_tags.save()
    except:
        log.warning("could not save tag file %s", to_fname, exc_info=True)
        success = False

    return success