def proc_htrc_coll(coll_dir, ignore=['.json', '.log', '.err']):
    books = os.listdir(coll_dir)
    books = filter_by_suffix(books, ignore)
    
    for book in books:
        # For debugging
        # if book == 'uc2.ark+=13960=t1zc80k1p':
        # if book == 'uc2.ark+=13960=t8tb11c8g':
        # if book == 'uc2.ark+=13960=t74t6gz6r':
        proc_htrc_book(book, coll_dir, ignore=ignore)
Given a collection, cleans up plain page files for books in the collection.
dataset/ETHPy150Open inpho/vsm/vsm/extensions/htrc.py/proc_htrc_coll