The PDFDocument allows manipulation of PDF documents, including facilities for merging pages, setting document open behavior, adding file attachments, and creating or changing document security settings. PDFDocumentOpen and PDFDocumentCreate are two functions that provide a reference to a PDFDocument object.
Example: Creating a Blank PDF Document
pdfPath = r"c:\temp\my.pdf"
pdfDoc = arcpy.mapping.PDFDocumentCreate(pdfPath)
#Commit changes and delete variable reference
pdfDoc.saveAndClose()
del pdfDoc
*Always call saveAndClose(), or the pdf will not appear on the file system.
Example: Opening a PDF Document and update properties
import arcpy
pdfDoc = arcpy.mapping.PDFDocumentOpen(r"C:\Project\ParcelAtlasMapBook.pdf")
pdfDoc.updateDocProperties(pdf_title="Atlas Map",
pdf_author="ESRI",
pdf_subject="Map Book",
pdf_keywords="Atlas; Map Books",
pdf_open_view="USE_THUMBS",
pdf_layout="SINGLE_PAGE")
pdfDoc.saveAndClose()
del pdfDoc
The mapping module in ArcPay allows for a host of properties to be updated as in the example above.
More examples and a full explanation of the object can be found here.