Rename the videos downloaded from CS161 - Tim Roughgarden

cs161_renamer.py

#!/usr/bin/env python

# CS 161 - Design and Analysis of Algorithms - Tim Roughgarden
#
# Script to rename FLV files using their XML containing metadata.
# I personally prefer the blackboard videos, so wrote a script to rename the
# videos to have proper titles.
#
# This is a script that gets job done, not something you'd want to integrate
# into some production code, so use it at your own risk.
#
# NOTE: Keep a copy of all the FLV files, just in case :-)
#
# Link to web page:
# http://openclassroom.stanford.edu/MainFolder/CoursePage.php?course=IntroToAlgorithms
#
# Link to XML and FLV files:
# http://openclassroom.stanford.edu/MainFolder/courses/IntroToAlgorithms/videos/


import os
import re
import string
import xml.etree.ElementTree


def get_title_and_file(xml_file_name):
    # Crappy, but gets the work done ...
    root = xml.etree.ElementTree.parse(xml_file_name).getroot()
    title = ""
    video_file = ""
    for child in root:
        if child.tag == "title":
            title = child.text
        elif child.tag == "videoFile":
            video_file = child.text
    if title == "" or video_file == "":
        raise ValueError("Invalid XML file %s passed" % xml_file_name)
    return title, video_file


def extract_lno_pno(file_name):
    p = re.compile("CS161L(\d+)P(\d+)\w?\.flv")
    m = p.match(file_name)
    if m is None:
        raise ValueError("Filename %s is not properly formatted" % file_name)
    return int(m.group(1)), int(m.group(2))


def gen_file_name(title, file_name):
    lno, pno = extract_lno_pno(file_name)
    valid_chars = "-_.() %s%s" % (string.ascii_letters, string.digits)
    valid_title = ''.join(c for c in title if c in valid_chars)
    return '%02d - %02d - %s.flv' % (lno, pno, valid_title)


def rename_file(xml_file_name):
    title, old_name = get_title_and_file(xml_file_name)
    new_name = gen_file_name(title, old_name)
    print "Renaming file '%s' to '%s'" % (old_name, new_name)
    os.rename(old_name, new_name)


if __name__ == "__main__":
    for filename in os.listdir("."):
        if filename.endswith(".xml"):
            try:
                rename_file(filename)
            except ValueError, e:
                print "Error: " + str(e)