py3: global name 'RectangleObject' is not defined

[DavidWiesner]

I try the Example from README in python 3.1. there are two issues:

1. command file() should be replaced with command open()
2. pdf.py needed the RectangleObject but is not imported.

here is an diff to solve the second issue

--- ../../old_pdf.py/pdf.py 2009-10-15 10:56:54.000000000 +0200
+++ pdf.py 2010-05-12 18:19:45.000000000 +0200
@@ -47,7 +47,7 @@
from .generic import (readObject, DictionaryObject, DecodedStreamObject,
NameObject, NumberObject, ArrayObject, IndirectObject,
ByteStringObject, StreamObject, NullObject, TextStringObject,

•    createStringObject, BooleanObject)
  

•    createStringObject, BooleanObject, RectangleObject)
  

  from .utils import (readNonWhitespace, readUntilWhitespace,
  ConvertFunctionsToVirtualList, PdfReadError, RC4_encrypt)
  thanks so far,
  david wiesner