Memmapped arrays don't pickle right. I know that to get them to
really pickle and restore identically, we would need some effort.
However, in the current status, pickling and restoring a memmapped array
leads to tracebacks that seem like they could be avoided.
I am attaching a patch with a test that shows the problem, and a fix.
Should I create a ticket, or is this light-enough to be applied
immediatly?
Cheers,
Gaël
Index: doc/release/1.3.0-notes.rst
===================================================================
--- doc/release/1.3.0-notes.rst (revision 8436)
+++ doc/release/1.3.0-notes.rst (working copy)
@@ -147,6 +147,12 @@
will install a numpy which works on any x86, even if the running computer
supports SSE set.
+Memapping in np.load
+~~~~~~~~~~~~~~~~~~~~
+
+np.load now support an optional argument to do transparent memory mapping
+of npy files.
+
Deprecated features
===================
Index: numpy/core/tests/test_memmap.py
===================================================================
--- numpy/core/tests/test_memmap.py (revision 8436)
+++ numpy/core/tests/test_memmap.py (working copy)
@@ -1,9 +1,10 @@
from tempfile import NamedTemporaryFile, mktemp
import os
import warnings
+import pickle
from numpy import memmap
-from numpy import arange, allclose
+from numpy import arange, allclose, all
from numpy.testing import *
class TestMemmap(TestCase):
@@ -90,5 +91,17 @@
finally:
memmap._close = _close
+ def test_pickle(self):
+ # Make sure that the memmap pickles without raising an exception
+ fp = memmap(self.tmpfp, dtype=self.dtype, mode='w+',
+ shape=self.shape)
+ fp[:] = self.data[:]
+ s = pickle.dumps(fp)
+ fp1 = pickle.loads(s)
+ # The copy can fail in the array_finalize
+ fp2 = fp1.copy()
+ self.assertTrue(all(fp == fp1))
+
+
if __name__ == "__main__":
run_module_suite()
Index: numpy/core/memmap.py
===================================================================
--- numpy/core/memmap.py (revision 8436)
+++ numpy/core/memmap.py (working copy)
@@ -244,9 +244,12 @@
def __array_finalize__(self, obj):
if hasattr(obj, '_mmap'):
self._mmap = obj._mmap
- self.filename = obj.filename
- self.offset = obj.offset
- self.mode = obj.mode
+ if hasattr(obj, 'filename'):
+ self.filename = obj.filename
+ if hasattr(obj, 'offset'):
+ self.offset = obj.offset
+ if hasattr(obj, 'mode'):
+ self.mode = obj.mode
else:
self._mmap = None
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