'The page number is the number of the page at the left most edge of the screen (starting from 0)'

@dynamic_property
def page_number(self):

    def fget(self):
        if self.in_paged_mode:
            return self.javascript('ans    =    0;    if    (window.paged_display)    ans    =    window.paged_display.column_boundaries()[0];    ans;', typ='int')
    def fset(self, val):
        if (self.in_paged_mode and self.loaded_javascript):
            self.javascript(('if    (window.paged_display)    window.paged_display.scroll_to_column(%d)' % int(val)))
            return True
    return property(fget=fget, fset=fset)
