Currently I am using the PyPDF 2 as a dependency.
I have encountered some encrypted files and handled
them as you normally would (in the following code):
PDF = PdfFileReader(file(pdf_filepath, 'rb'))
To Answer My Own Question: If you have ANY spaces in your file name, then PyPDF 2 decrypt function will ultimately fail despite returning a success code. Try to stick to underscores when naming your PDFs before you run them through PyPDF2.
Rather than "FDJKL492019 21490 ,LFS.pdf" do something like "FDJKL492019_21490_,LFS.pdf".