Why does pyPdf2.PdfFileReader() require a file object as an input?

csv.reader() doesn’t require a file object, nor does open(). Does pyPdf2.PdfFileReader() require a file object because of the complexity of the PDF format, or is there some other reason?

Answer

It’s just a matter of how the library was written. csv.reader allows any iterable that returns strings (which includes files). open is opening the file, so of course it doesn’t take an open file (although it can take an integer pointing at an open file descriptor). Typically, it is better to handle the file separately, usually within a with block so that it is closed properly.

with open('input.pdf', 'rb') as f:
    # do something with the file