'Retrieves a page by number from this PDF file.
:param int pageNumber: The page number to retrieve
(pages begin at zero)
:return: a :class:`PageObject<pdf.PageObject>` instance.
:rtype: :class:`PageObject<pdf.PageObject>`'

def getPage(self, pageNumber):

    if (self.flattenedPages == None):
        self._flatten()
    return self.flattenedPages[pageNumber]
