pypdf is a free and open-source pure-python PDF library capable of
splitting, merging, cropping, and transforming the pages of PDF files.
It can also add custom data, viewing options, and passwords to PDF
files. pypdf can retrieve text and metadata from PDFs as well.

pypdf is a descendant of PyPDF2, which was a fork from the original
pyPdf. (Both pyPdf and PyPDF2 are available on SBo.)