1 files changed, 43 insertions, 0 deletions
diff --git a/Mailman/SafeDict.py b/Mailman/SafeDict.py
new file mode 100644
index 000000000..d7b1004ff
--- /dev/null
+++ b/Mailman/SafeDict.py
@@ -0,0 +1,43 @@
+# Copyright (C) 1998,1999,2000,2001 by the Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software 
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+"""A `safe' dictionary for string interpolation."""
+
+from types import StringType
+from UserDict import UserDict
+
+
+
+class SafeDict(UserDict):
+    """Dictionary which returns a default value for unknown keys.
+
+    This is used in maketext so that editing templates is a bit more robust.
+    """
+    def __init__(self, d=None):
+        # optional initial dictionary is a Python 1.5.2-ism.  Do it this way
+        # for portability
+        UserDict.__init__(self)
+        if d is not None:
+            self.update(d)
+
+    def __getitem__(self, key):
+        try:
+            return self.data[key]
+        except KeyError:
+            if type(key) == StringType:
+                return '%('+key+')s'
+            else:
+                return '<Missing key: %s>' % `key`