"""Framework for getting filetype-specific metadata.

Instantiate appropriate class with filename.  Returned object acts like a
dictionary, with key-value pairs for each piece of metadata.
    import fileinfo
    info = fileinfo.MP3FileInfo("/music/ap/mahadeva.mp3")
    print "\\n".join(["%s=%s" % (k, v) for k, v in info.items()])

Or use listDirectory function to get info on all files in a directory.
    for info in fileinfo.listDirectory("/music/ap/", [".mp3"]):
        ...

Framework can be extended by adding classes for particular file types, e.g.
HTMLFileInfo, MPGFileInfo, DOCFileInfo.  Each class is completely responsible for
parsing its files appropriately; see MP3FileInfo for example.
"""
import os
import sys
from UserDict import UserDict

def stripnulls(data):
    "strip whitespace and nulls"
    return data.replace("\00", "").strip()

class FileInfo(UserDict):
    "store file metadata"
    def __init__(self, filename=None):
        UserDict.__init__(self)
        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  This program's output depends on the files on your hard drive. To get meaningful output, you'll need to change the directory path to point to a directory of MP3 files on your own machine.  

This is the output I got on my machine. Your output will be different, unless, by some startling coincidence, you share my exact taste in music. 

album=
artist=Ghost in the Machine
title=A Time Long Forgotten (Concept
genre= 31 
name=/music/_singles/a_time_long_forgotten_con.mp3
year= 1999 
comment=http://mp3.com/ghostmachine

album=Rave Mix
artist=***DJ MARY-JANE***
title=HELLRAISER****Trance from Hell
genre= 31 
name=/music/_singles/hellraiser.mp3
year= 2000 
comment=http://mp3.com/DJMARYJANE

album=Rave Mix
artist=***DJ MARY-JANE***
title=KAIRO****THE BEST GOA
genre= 31 
name=/music/_singles/kairo.mp3
year= 2000 
comment=http://mp3.com/DJMARYJANE

album=Journeys
artist=Masters of Balance
title=Long Way Home
genre= 31 
name=/music/_singles/long_way_home1.mp3
year= 2000 
comment=http://mp3.com/MastersofBalan

album=
artist=The Cynic Project
title=Sidewinder
genre= 18 
name=/music/_singles/sidewinder.mp3
year= 2000 
comment=http://mp3.com/cynicproject

album=Digitosis@128k
artist=VXpanded
title=Spinning
genre= 255 
name=/music/_singles/spinning.mp3
year= 2000 
comment=http://mp3.com/artists/ 95 /vxp