Convert/Write PDF 到 RAM 作为类文件对象，以便进一步使用它

Question

我的脚本生成 PDF (PyPDF2.pdf.PdfFileWriter object) 并将其存储在变量中。我需要在脚本中进一步使用它作为 file-like object。但现在我必须先把它写到硬盘上。然后我必须将它作为文件打开才能使用它。

为了防止这种不必要的 writing/reading 操作，我找到了很多解决方案 - StringIO、BytesIO 等等。但是我找不到对我的情况有什么帮助。

据我了解 - 我需要 "convert"（或写入 RAM）PyPDF2.pdf.PdfFileWriter object 到 file-like object 才能直接使用它。

或者有另一种方法完全适合我的情况？

更新 - 这是代码示例

from pdfrw import PdfReader, PdfWriter, PageMerge
from PyPDF2 import PdfFileReader, PdfFileWriter


red_file = PdfFileReader(open("file_name.pdf", 'rb'))

large_pages_indexes = [1, 7, 9]

large = PdfFileWriter()
for i in large_pages_indexes:
    p = red_file.getPage(i)
    large.addPage(p)

# here final data have to be written (I would like to avoid that)
with open("virtual_file.pdf", 'wb') as tmp:
  large.write(tmp)

# here I need to read exported "virtual_file.pdf" (I would like to avoid that too)
with open("virtual_file.pdf", 'rb') as tmp:
  pdf = PdfReader(tmp) # here I'm starting to work with this file using another module "pdfrw"
  print(pdf)

Answer 1

为了避免慢速磁盘 I/O 看来您要更换

with open("virtual_file.pdf", 'wb') as tmp:
  large.write(tmp)

with open("virtual_file.pdf", 'rb') as tmp:
  pdf = PdfReader(tmp)

与

buf = io.BytesIO()
large.write(buf)
buf.seek(0)
pdf = PdfReader(buf)

此外，buf.getvalue() 可供您使用。

Convert/Write PDF 到 RAM 作为类文件对象，以便进一步使用它

Convert/Write PDF to RAM as file-like object for further working with it

python

python-3.x

pypdf2