Django mini-series

I'm running a Django mini-series on Will Larson's blog, called Wielding Django. So far I have written:

1. Minimalism


2. Up to Speed


3. JSON, Object-Oriented Views, and Starting a Real App

I'm mainly posting this to provide a place for discussion in the comments.

mp3rename

I had a sizable collection of sermons that were named very badly (e.g., just the name). I was unsatisfied with all the mp3 renaming tools I found; they wouldn't get the output I wanted, or wouldn't read id3v2 tags, or etc. So, using python-eyeD3, I wrote my own.

#!/usr/bin/env python

import eyeD3, os, sys

default_subs = {
    ':': ' -',
}

bad_chars = ['?','/',':']    

def clean(x, subs=default_subs, bad_chars=bad_chars):
    for a,b in subs.iteritems():
        x = x.replace(a,b)
    for c in bad_chars:
        x = x.replace(c,'')
    return x

def do_rename_file(fname):
    tag = eyeD3.Tag()
    tag.link(fname)

    name = []

    num = tag.getTrackNum()[0]
    if num:
        name.append('%02d' % num)
        name.append('-')
    
    artist = tag.getArtist()
    if artist:
        name.append(clean(artist))
        name.append('-')

    title = tag.getTitle()
    if title:
        name.append(clean(title))

    name = ''.join(name)

    if not title:
        print 'Not renaming %s - not enough tag data' % fname
        return

    name = name+'.mp3'
    
    print 'Renaming "%s" to "%s": (OK,q,sub_name)' % (fname, name)
    x=raw_input()
    if len(x) > 2:
        name = x
    elif len(x) > 0:
        print 'OK, skipping.'
        return

    os.rename(fname, name)

if __name__=='__main__':
    for f in sys.argv[1:]:
        do_rename_file(f)

You can modify the output format by... changing the code. But python is pretty readable.