Python: PDFファイル内の全ページを任意のサイズに変換する

from enum import Enum
from io import BytesIO
import PyPDF2


class PDFSizeParam(tuple, Enum):
    PX_72DPI_A4 = (595, 847)
    PX_300DPI_A4 = (2480, 3508)
    PX_350DPI_A4 = (2894, 4093)


def scale_pdf_to(pdf_bytes: bytes, scale_to: PDFSizeParam = PDFSizeParam.PX_72DPI_A4) -> bytes:
    reader = PyPDF2.PdfFileReader(BytesIO(pdf_bytes))
    num_pages = reader.getNumPages()
    pages = [reader.getPage(i) for i in range(num_pages)]
    [page.scaleTo(scale_to.value[0], scale_to.value[1]) for page in pages]
    writer: PyPDF2.PdfFileWriter = PyPDF2.PdfFileWriter()
    [writer.addPage(page) for page in pages]
    temp_pdf: BytesIO = BytesIO()
    writer.write(temp_pdf)
    temp_pdf.seek(0)
    return temp_pdf.read()

bytes <-> File読み書きは割愛。