[Matrix-SIG] problems pickling arrays of PyObjects

[Alan Grossfield]

Konrad>Now that I understand what the problem really is, the explanation is
Konrad>fairly simple: There is no provision to pickle general-object arrays
Konrad>at all in the current NumPy code, as is obvious from a quick glance at
Konrad>module Numeric. The pickled file contains simply the addresses of the
Konrad>elements.
Konrad>
Konrad>Array pickling needs a serious revision anyway (with cPickle support),

Here's a trivial patch to Numeric.py, which makes it complain if
you try to pickle an array of PyObjects.

diff -u Numeric.py.orig Numeric.py
--- Numeric.py.orig     Tue Oct 27 13:15:24 1998
+++ Numeric.py  Tue Oct 27 13:19:50 1998
@@ -186,6 +186,10 @@
 # byte-order issues for  portability.
 
 def DumpArray(m, fp):    
+
+       # patch -- check for array of PyObjects
+       if m.typecode() == 'O': 
+            raise TypeError, "Numeric Pickler can't pickle arrays of Objects"
        s = m.shape
        if LittleEndian: endian = "L"
        else: endian = "B"

Alan Grossfield
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