python-2.5.2/win32/Lib/anydbm.py
changeset 0 ae805ac0140d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python-2.5.2/win32/Lib/anydbm.py	Fri Apr 03 17:19:34 2009 +0100
@@ -0,0 +1,83 @@
+"""Generic interface to all dbm clones.
+
+Instead of
+
+        import dbm
+        d = dbm.open(file, 'w', 0666)
+
+use
+
+        import anydbm
+        d = anydbm.open(file, 'w')
+
+The returned object is a dbhash, gdbm, dbm or dumbdbm object,
+dependent on the type of database being opened (determined by whichdb
+module) in the case of an existing dbm. If the dbm does not exist and
+the create or new flag ('c' or 'n') was specified, the dbm type will
+be determined by the availability of the modules (tested in the above
+order).
+
+It has the following interface (key and data are strings):
+
+        d[key] = data   # store data at key (may override data at
+                        # existing key)
+        data = d[key]   # retrieve data at key (raise KeyError if no
+                        # such key)
+        del d[key]      # delete data stored at key (raises KeyError
+                        # if no such key)
+        flag = key in d   # true if the key exists
+        list = d.keys() # return a list of all existing keys (slow!)
+
+Future versions may change the order in which implementations are
+tested for existence, add interfaces to other dbm-like
+implementations.
+
+The open function has an optional second argument.  This can be 'r',
+for read-only access, 'w', for read-write access of an existing
+database, 'c' for read-write access to a new or existing database, and
+'n' for read-write access to a new database.  The default is 'r'.
+
+Note: 'r' and 'w' fail if the database doesn't exist; 'c' creates it
+only if it doesn't exist; and 'n' always creates a new database.
+
+"""
+
+class error(Exception):
+    pass
+
+_names = ['dbhash', 'gdbm', 'dbm', 'dumbdbm']
+_errors = [error]
+_defaultmod = None
+
+for _name in _names:
+    try:
+        _mod = __import__(_name)
+    except ImportError:
+        continue
+    if not _defaultmod:
+        _defaultmod = _mod
+    _errors.append(_mod.error)
+
+if not _defaultmod:
+    raise ImportError, "no dbm clone found; tried %s" % _names
+
+error = tuple(_errors)
+
+def open(file, flag = 'r', mode = 0666):
+    # guess the type of an existing database
+    from whichdb import whichdb
+    result=whichdb(file)
+    if result is None:
+        # db doesn't exist
+        if 'c' in flag or 'n' in flag:
+            # file doesn't exist and the new
+            # flag was used so use default type
+            mod = _defaultmod
+        else:
+            raise error, "need 'c' or 'n' flag to open new db"
+    elif result == "":
+        # db type cannot be determined
+        raise error, "db type could not be determined"
+    else:
+        mod = __import__(result)
+    return mod.open(file, flag, mode)