diff options
| -rw-r--r-- | Doc/lib/libshelve.tex | 38 | ||||
| -rw-r--r-- | Lib/shelve.py | 17 | ||||
| -rw-r--r-- | Lib/test/test_shelve.py | 51 | ||||
| -rw-r--r-- | Misc/NEWS | 4 |
4 files changed, 98 insertions, 12 deletions
diff --git a/Doc/lib/libshelve.tex b/Doc/lib/libshelve.tex index 1e02c7b..e8491be 100644 --- a/Doc/lib/libshelve.tex +++ b/Doc/lib/libshelve.tex @@ -19,7 +19,8 @@ arbitrary object): \begin{verbatim} import shelve -d = shelve.open(filename) # open, with (g)dbm filename -- no suffix +d = shelve.open(filename) # open -- file may get suffix added by low-level + # library d[key] = data # store data at key (overwrites old data if # using an existing key) @@ -54,8 +55,10 @@ cause the database to refuse updates. \refbimodindex{gdbm} \item -Dependent on the implementation, closing a persistent dictionary may -or may not be necessary to flush changes to disk. +Depending on the implementation, closing a persistent dictionary may +or may not be necessary to flush changes to disk. The \method{__del__} +method of the \class{Shelf} class calls the \method{close} method, so the +programmer generally need not do this explicitly. \item The \module{shelve} module does not support \emph{concurrent} read/write @@ -67,10 +70,37 @@ requires knowledge about the database implementation used. \end{itemize} +\begin{classdesc}{Shelf}{dict\optional{, binary=False}} +A subclass of \class{UserDict.DictMixin} which stores pickled values in the +\var{dict} object. If the \var{binary} parameter is \constant{True}, binary +pickles will be used. This can provide much more compact storage than plain +text pickles, depending on the nature of the objects stored in the databse. +\end{classdesc} + +\begin{classdesc}{BsdDbShelf}{dict\optional{, binary=False}} +A subclass of \class{Shelf} which exposes \method{first}, \method{next}, +{}\method{previous}, \method{last} and \method{set_location} which are +available in the \module{bsddb} module but not in other database modules. +The \var{dict} object passed to the constructor must support those methods. +This is generally accomplished by calling one of \function{bsddb.hashopen}, +\function{bsddb.btopen} or \function{bsddb.rnopen}. The optional +\var{binary} parameter has the same interpretation as for the \class{Shelf} +class. +\end{classdesc} + +\begin{classdesc}{DbfilenameShelf}{dict\optional{, flag='c'}\optional{, binary=False}} +A subclass of \class{Shelf} which accepts a filename instead of a dict-like +object. The underlying file will be opened using \function{anydbm.open}. +By default, the file will be created and opened for both read and write. +The optional \var{binary} parameter has the same interpretation as for the +\class{Shelf} class. +\end{classdesc} \begin{seealso} \seemodule{anydbm}{Generic interface to \code{dbm}-style databases.} - \seemodule{dbhash}{BSD \code{db} database interface.} + \seemodule{bsddb}{BSD \code{db} database interface.} + \seemodule{dbhash}{Thin layer around the \module{bsddb} which provides an + \function{open} function like the other database modules.} \seemodule{dbm}{Standard \UNIX{} database interface.} \seemodule{dumbdbm}{Portable implementation of the \code{dbm} interface.} \seemodule{gdbm}{GNU database interface, based on the \code{dbm} interface.} diff --git a/Lib/shelve.py b/Lib/shelve.py index 7a318a6..e262d79 100644 --- a/Lib/shelve.py +++ b/Lib/shelve.py @@ -51,8 +51,9 @@ class Shelf(UserDict.DictMixin): See the module's __doc__ string for an overview of the interface. """ - def __init__(self, dict): + def __init__(self, dict, binary=False): self.dict = dict + self.binary = binary def keys(self): return self.dict.keys() @@ -77,7 +78,7 @@ class Shelf(UserDict.DictMixin): def __setitem__(self, key, value): f = StringIO() - p = Pickler(f) + p = Pickler(f, self.binary) p.dump(value) self.dict[key] = f.getvalue() @@ -112,8 +113,8 @@ class BsdDbShelf(Shelf): See the module's __doc__ string for an overview of the interface. """ - def __init__(self, dict): - Shelf.__init__(self, dict) + def __init__(self, dict, binary=False): + Shelf.__init__(self, dict, binary) def set_location(self, key): (key, value) = self.dict.set_location(key) @@ -148,16 +149,16 @@ class DbfilenameShelf(Shelf): See the module's __doc__ string for an overview of the interface. """ - def __init__(self, filename, flag='c'): + def __init__(self, filename, flag='c', binary=False): import anydbm - Shelf.__init__(self, anydbm.open(filename, flag)) + Shelf.__init__(self, anydbm.open(filename, flag), binary) -def open(filename, flag='c'): +def open(filename, flag='c', binary=False): """Open a persistent dictionary for reading and writing. Argument is the filename for the dbm database. See the module's __doc__ string for an overview of the interface. """ - return DbfilenameShelf(filename, flag) + return DbfilenameShelf(filename, flag, binary) diff --git a/Lib/test/test_shelve.py b/Lib/test/test_shelve.py new file mode 100644 index 0000000..29af82e --- /dev/null +++ b/Lib/test/test_shelve.py @@ -0,0 +1,51 @@ +import os +import unittest +import shelve +import glob +from test import test_support + +class TestCase(unittest.TestCase): + + fn = "shelftemp.db" + + def test_ascii_file_shelf(self): + try: + s = shelve.open(self.fn, binary=False) + s['key1'] = (1,2,3,4) + self.assertEqual(s['key1'], (1,2,3,4)) + s.close() + finally: + for f in glob.glob(self.fn+"*"): + os.unlink(f) + + def test_binary_file_shelf(self): + try: + s = shelve.open(self.fn, binary=True) + s['key1'] = (1,2,3,4) + self.assertEqual(s['key1'], (1,2,3,4)) + s.close() + finally: + for f in glob.glob(self.fn+"*"): + os.unlink(f) + + def test_in_memory_shelf(self): + d1 = {} + s = shelve.Shelf(d1, binary=False) + s['key1'] = (1,2,3,4) + self.assertEqual(s['key1'], (1,2,3,4)) + s.close() + d2 = {} + s = shelve.Shelf(d2, binary=True) + s['key1'] = (1,2,3,4) + self.assertEqual(s['key1'], (1,2,3,4)) + s.close() + + self.assertEqual(len(d1), 1) + self.assertNotEqual(d1, d2) + +def test_main(): + test_support.run_unittest(TestCase) + + +if __name__ == "__main__": + test_main() @@ -440,6 +440,10 @@ Library all dictionary methods. This eases the transition to persistent storage for scripts originally written with dictionaries in mind. +- shelve.open and the various classes in shelve.py now accept an optional + binary flag, which defaults to False. If True, the values stored in the + shelf are binary pickles. + - A new package, logging, implements the logging API defined by PEP 282. The code is written by Vinay Sajip. |