python rotate pdf pages

1    import PyPDF2
2
3    pdf_in = open('original.pdf', 'rb')
4    pdf_reader = PyPDF2.PdfFileReader(pdf_in)
5    pdf_writer = PyPDF2.PdfFileWriter()
6
7    for pagenum in range(pdf_reader.numPages):
8        page = pdf_reader.getPage(pagenum)
9        page.rotateClockwise(180)
10        pdf_writer.addPage(page)
11
12    pdf_out = open('rotated.pdf', 'wb')
13    pdf_writer.write(pdf_out)
14    pdf_out.close()
15    pdf_in.close()
16