Python: Läsning och skrivning av fil.

# Tracklist.txt
# Generated by ID3TagWriter_v1.0 by eriikh

Berätta det för lina - Lillasyster
Kräkas - Lillasyster
Svin - Lillasyster
Hårdrock - Lillasyster
Nu har jag fått nog - Lillasyster
Barn utan ben - Lillasyster
Kometen - Lillasyster
Spänn hjälmen - Lillasyster
Stukaplan - Lillasyster
Varfördärför - Lillasyster

# ID3Tagwriter_1.0 by eriikh
# This text should not be removed
# Everything before "Main:" comes from www.diveintopython.org and are written by Mark Pilgrim 2001.

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)}
    
    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]

# Main:
if __name__ == "__main__":                      # Forsakra att programmet anvands som fristaende 
    trackfile = open("tracklist.txt", "w")
    trackfile.write("# Tracklist.txt")
    trackfile.write("\n") 
    trackfile.write("# Generated by ID3TagWriter_v1.0 by eriikh")
    trackfile.write("\n")
    trackfile.write("\n") 
    for info in listDirectory("", [".mp3"]):    # "" = leta i egen mapp
         trackfile.write(info["title"])         # Skriv ut title-tag
         trackfile.write(" - ")
         trackfile.write(info["artist"])        # Skriv ut artist-tag
         trackfile.write("\n")                  # Retur      
    trackfile.close()                           # Stang fil
    print file("tracklist.txt").read()          # Skriv ut fil i kommandofonstret

if info["title"] == NULL | info["artist"] == NULL then 
       trackfile.write(filename)             # Bör kanske strippas på filändelsen om den åker med
else       
       trackfile.write(info["title"])         # Skriv ut title-tag
       trackfile.write(" - ")
       trackfile.write(info["artist"])       # Skriv ut artist-tag
       trackfile.write("\n")                  # Retur      
end