Initial import from Docker volume

model/descriptors.py

@@ -0,0 +1,34 @@
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
+import functools
+
+
+class dualmethod(object):
+    """Descriptor implementing combination of class and instance method
+
+    When called on an instance, the class is passed as the first argument and a
+    list with the instance as the second.
+    When called on a class, the class itsefl is passed as the first argument.
+
+    >>> class Example(object):
+    ...     @dualmethod
+    ...     def method(cls, instances):
+    ...         print(len(instances))
+    ...
+    >>> Example.method([Example()])
+    1
+    >>> Example().method()
+    1
+    """
+    def __init__(self, func):
+        self.func = func
+
+    def __get__(self, instance, owner):
+
+        @functools.wraps(self.func)
+        def newfunc(*args, **kwargs):
+            if instance:
+                return self.func(owner, [instance], *args, **kwargs)
+            else:
+                return self.func(owner, *args, **kwargs)
+        return newfunc