"""Framework for getting filetype-specific metadata.This is the same as fileinfo.py with one difference:instead of inheriting from UserDict, we inherit directly from dict.This capability was introduced in Python 2.2, and makes UserDictunnecessary (along with its cousins, UserList and UserString).This program is part of "Dive Into Python", a free Python book forexperienced programmers.  Visit http://diveintopython.org/ for thelatest version."""__author__ = "Mark Pilgrim (mark@diveintopython.org)"__version__ = "$Revision: 1.2 $"__date__ = "$Date: 2004/05/05 21:57:19 $"__copyright__ = "Copyright (c) 2001 Mark Pilgrim"__license__ = "Python"import osimport sysdef stripnulls(data):    "strip whitespace and nulls"    return data.replace("\00", " ").strip()class FileInfo(dict):    "store file metadata"    def __init__(self, filename=None):        self["name"] = filename    class MP3FileInfo(FileInfo):    "store ID3v1.0 MP3 tags"    tagDataMap = {"title"   : (  3,  33, stripnulls),                  "artist"  : ( 33,  63, stripnulls),                  "album"   : ( 63,  93, stripnulls),                  "year"    : ( 93,  97, stripnulls),                  "comment" : ( 97, 126, stripnulls),                  "genre"   : (127, 128, ord)}        def __parse(self, filename):        "parse ID3v1.0 tags from MP3 file"        self.clear()        try:            fsock = open(filename, "rb", 0)            try:                fsock.seek(-128, 2)                tagdata = fsock.read(128)            finally:                fsock.close()            if tagdata[:3] == 'TAG':                for tag, (start, end, parseFunc) in self.tagDataMap.items():                    self[tag] = parseFunc(tagdata[start:end])        except IOError:            pass    def __setitem__(self, key, item):        if key == "name" and item:            self.__parse(item)        FileInfo.__setitem__(self, key, item)def listDirectory(directory, fileExtList):    "get list of file info objects for files of particular extensions"    fileList = [os.path.normcase(f) for f in os.listdir(directory)]    fileList = [os.path.join(directory, f) for f in fileList \                if os.path.splitext(f)[1] in fileExtList]    def getFileInfoClass(filename, module=sys.modules[FileInfo.__module__]):        "get file info class from filename extension"        subclass = "%sFileInfo" % os.path.splitext(filename)[1].upper()[1:]        return hasattr(module, subclass) and getattr(module, subclass) or FileInfo    return [getFileInfoClass(f)(f) for f in fileList]if __name__ == "__main__":    for info in listDirectory("/music/_singles/", [".mp3"]):        print "\n".join(["%s=%s" % (k, v) for k, v in info.items()])        print