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authorGuido van Rossum <guido@python.org>1997-06-06 21:12:45 (GMT)
committerGuido van Rossum <guido@python.org>1997-06-06 21:12:45 (GMT)
commit914c938cc553fe668ea2987d7d429b2c246906a8 (patch)
tree189457b444921dcde7acdbe7c6a67cb881e95d8d /Lib/shelve.py
parentf668d17e010ea5a09846d2e6a994511ca7ad28eb (diff)
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Use cPickle and cStringIO when available.
Diffstat (limited to 'Lib/shelve.py')
-rw-r--r--Lib/shelve.py50
1 files changed, 30 insertions, 20 deletions
diff --git a/Lib/shelve.py b/Lib/shelve.py
index 8f709a2..b159e61 100644
--- a/Lib/shelve.py
+++ b/Lib/shelve.py
@@ -28,8 +28,17 @@ Dependent on the implementation, closing a persistent dictionary may
or may not be necessary to flush changes to disk.
"""
-import pickle
-import StringIO
+# Try using cPickle and cStringIO if available.
+
+try:
+ from cPickle import Pickler, Unpickler
+except ImportError:
+ from pickle import Pickler, Unpickler
+
+try:
+ from cStringIO import StringIO
+except ImportError:
+ from StringIO import StringIO
class Shelf:
@@ -52,12 +61,12 @@ class Shelf:
return self.dict.has_key(key)
def __getitem__(self, key):
- f = StringIO.StringIO(self.dict[key])
- return pickle.Unpickler(f).load()
+ f = StringIO(self.dict[key])
+ return Unpickler(f).load()
def __setitem__(self, key, value):
- f = StringIO.StringIO()
- p = pickle.Pickler(f)
+ f = StringIO()
+ p = Pickler(f)
p.dump(value)
self.dict[key] = f.getvalue()
@@ -80,11 +89,12 @@ class Shelf:
class BsdDbShelf(Shelf):
"""Shelf implementation using the "BSD" db interface.
- The actual database is opened using one of thethe "bsddb" modules
- "open" routines (i.e. bsddb.hashopen, bsddb.btopen or bsddb.rnopen.)
+ This adds methods first(), next(), previous(), last() and
+ set_location() that have no counterpart in [g]dbm databases.
- This class is initialized with the the database object
- returned from one of the bsddb open functions.
+ The actual database must be opened using one of the "bsddb"
+ modules "open" routines (i.e. bsddb.hashopen, bsddb.btopen or
+ bsddb.rnopen) and passed to the constructor.
See the module's __doc__ string for an overview of the interface.
"""
@@ -94,28 +104,28 @@ class BsdDbShelf(Shelf):
def set_location(self, key):
(key, value) = self.dict.set_location(key)
- f = StringIO.StringIO(value)
- return (key, pickle.Unpickler(f).load())
+ f = StringIO(value)
+ return (key, Unpickler(f).load())
def next(self):
(key, value) = self.dict.next()
- f = StringIO.StringIO(value)
- return (key, pickle.Unpickler(f).load())
+ f = StringIO(value)
+ return (key, Unpickler(f).load())
def previous(self):
(key, value) = self.dict.previous()
- f = StringIO.StringIO(value)
- return (key, pickle.Unpickler(f).load())
+ f = StringIO(value)
+ return (key, Unpickler(f).load())
def first(self):
(key, value) = self.dict.first()
- f = StringIO.StringIO(value)
- return (key, pickle.Unpickler(f).load())
+ f = StringIO(value)
+ return (key, Unpickler(f).load())
def last(self):
(key, value) = self.dict.last()
- f = StringIO.StringIO(value)
- return (key, pickle.Unpickler(f).load())
+ f = StringIO(value)
+ return (key, Unpickler(f).load())
class DbfilenameShelf(Shelf):