A python script for preparing files for upload to the Lectio system by adding student numbers to file names based on a reference folder

lectiolize.py

#!/usr/bin/env python2.7
"""
Lectiolize: A python script for preparing files for upload to the Lectio system 
by adding student numbers to file names based on a reference folder.

(C) janus@insignificancegalore.net, 2014
"""

from collections import namedtuple
import re
import os, os.path
import unicodedata 
import itertools
import collections

_lectiolize_lectioname = re.compile('(\d+)_([^_]+)_')
def normalize(s):		
	"""
	Normalize by throwing away all non-ascii characters after composing
	"""
	return unicodedata.normalize('NFKC', s).encode('ascii', 'ignore')

def partmatch(ref, s):
	return (len(s)==1 and ref.startswith(s)) or ref == s

class NameAndNumber:
	def __init__(self, name, number):
		self.name = name
		self.number = number

	def matches(self, name):
	 	"""
	 	Decide whether self.name matches named
	 	This is the case if the parts of name matches the a subset of the 
	 	parts of self.name, in the order they appear.
	 	Parts match if they are a matching initial or the full name
	 	"""
	 	ref = iter(normalize(self.name).split(' '))
	 	tgt = normalize(name).split(' ')
	 	return all(next((r for r in ref if partmatch(r,s)), None) for s in tgt)

def get_refs_folder(folder):
	"""
	Return a list of NameAndNumber objects, corresponding to all files in folder 
	of the form <number>_<name with spaces>[_<title>].ext
	"""
	return [
		NameAndNumber(m.group(2), m.group(1)) for m in (
			_lectiolize_lectioname.match(f) for f in os.listdir(unicode(folder))
			) if m is not None ]

def rename_matches(target_folder, references, title = None, dryrun = False):
	"""
	Rename each file in target_folder that matches exactly one
	reference which is not matched by any other file in the target folder
	"""

	is_assigned = collections.defaultdict(list)
	is_bad = {}
	files = os.listdir(unicode(target_folder))

	for f in files:
		f_name = os.path.splitext(f)[0]
		has_match = False
		for ref in references:
			if ref.matches(f_name):
				is_assigned[ref].append(f)
				if has_match:
					is_bad[f] = True
				has_match = True

	for ref, files in is_assigned.iteritems():
		if not len(files) == 1: 
			if len(files) == 0:
				print 'No match for %s'%ref.number
			else:
				print 'Multiple matches for %s: {%s}'%(ref.number, ', '.join(files))
		else:
			filename = files[0]
			if filename in is_bad:
				print '%s matched %s but also others'%(filename, ref.number)
				continue

			# all is good
			if title is None:
				newname = '%s_%s'%(ref.number, filename)
			else:
				filename_parts = os.path.splitext(filename)
				newname = '%s_%s_%s%s'%(ref.number, filename_parts[0], title, filename_parts[1])
			print 'Renaming %20s to %s'%(filename, newname)
			if not dryrun:
				os.rename(os.path.join(target_folder, filename), os.path.join(target_folder, newname))


def main():
	import argparse
	parser = argparse.ArgumentParser(description="""
Rename a set of files to lectio format nr_name_title.ext based on 
a reference folder or list of names and numbers
The files to rename should be named
<First name> [initial_or_surname ]+.<extension>


Example use:
lectiolize.py --title 'Crazy TLA' -r folder_from_lectio 'my folder'
		""", formatter_class = argparse.RawTextHelpFormatter)
	parser.add_argument('--reference_folder', '-r', 
		help = 'A folder to scan for files with correct numbers')
	parser.add_argument('--title', '-t', default = None,
		help = 'Title to add to end of renamed files')
	parser.add_argument('--dryrun', '-n', action = 'store_true', default = False,
		help = 'Only show what would be done')
	parser.add_argument('target_folder', 
		help = 'Folder in which to rename files')

	args = parser.parse_args()
	refs = get_refs_folder(args.reference_folder)
	rename_matches(args.target_folder, refs, args.title, dryrun = args.dryrun)

if __name__ == '__main__':
	main()