Initial import from Docker volume

tools/immutabledict.py

@@ -0,0 +1,26 @@
+# This file is part of Tryton.  The COPYRIGHT file at the toplevel of this
+# repository contains the full copyright notices and license terms.
+from copy import deepcopy
+
+
+class ImmutableDict(dict):
+
+    __slots__ = ()
+
+    def _not_allowed(cls, *args, **kwargs):
+        raise TypeError("Operation not allowed on ImmutableDict")
+
+    def __deepcopy__(self, memo):
+        return ImmutableDict(
+            (k, deepcopy(v, memo=memo)) for k, v in self.items())
+
+    __setitem__ = _not_allowed
+    __delitem__ = _not_allowed
+    __ior__ = _not_allowed
+    clear = _not_allowed
+    pop = _not_allowed
+    popitem = _not_allowed
+    setdefault = _not_allowed
+    update = _not_allowed
+
+    del _not_allowed