Some kind of cognitive intereference wave

I was doing some BeautifulSoup kitchen work on aeronautics course 16-225 and wanted to automate the process of dealing with the lectures and organizing the material. So I souped it up to get the pdfs of the lectures and this is what I see. Somebody couldn't make up their mind whether they were lectures, pdf pdfs , lecture notes, camel case, lessons, format %2d or %1d, or just l something and how many underscores to use to separate. I really have to wonder.

My soup skills continue to improve as do my python math skills as well as wave mechanics and understanding of quantum mechanics nomenclature. It isn't a big trick to reorganize and rename these in the way I like, but I thought it interesting that the table looks so neat and well formatted, but inside it is something else.

motey@motey-desktop:~/Notes/Programming/Python$ python soup6.py look
  1 lecture_01.pdf
  2 lecture_02.pdf
  3 lesson_3_Notes.pdf
  4 lesson_4_Notes.pdf
  5 lesson_5_notes.pdf
  6 lecture_06_notes.pdf
  7 lecture_07_Notes.pdf
  8 lecture__8.pdf
  9 lesson__9_Notes.pdf
 10 l_10.pdf
 11 lesson_11.pdf
 12 lesson_12.pdf
 13 lesson__13.pdf
 14 lecture_14_notes.pdf
 15 lesson_15.pdf
 16 lesson__16_Notes.pdf
 17 lesson__17_Notes_pdf.pdf
 18 lesson_18.pdf
 19 lesson_19_notes.pdf
 20 lecture_20.pdf
 21 lecture_21.pdf
 22 lecture_22.pdf
 23 lecture_23.pdf
 24 Lecture_24.pdf
 25 Lecture_25.pdf
 26 Lecture_26.pdf