ext.lazy_property: allow resetting lazy properties

1 files changed, 25 insertions, 1 deletions

diff --git a/ranger/ext/lazy_property.py b/ranger/ext/lazy_property.py
index 92dc309d..c468a8c9 100644
--- a/ranger/ext/lazy_property.py
+++ b/ranger/ext/lazy_property.py
@@ -1,4 +1,6 @@
-# From http://blog.pythonisito.com/2008/08/lazy-descriptors.html
+# This file is part of ranger, the console file manager.
+# License: GNU GPL version 3, see the file "AUTHORS" for details.
+# Based on http://blog.pythonisito.com/2008/08/lazy-descriptors.html
 
 from __future__ import (absolute_import, division, print_function)
 
@@ -17,6 +19,22 @@ class lazy_property(object):  # pylint: disable=invalid-name,too-few-public-meth
     42
     >>> foo.answer
     42
+    >>> foo.answer__reset()
+    >>> foo.answer
+    calculating answer...
+    42
+    >>> foo.answer
+    42
+
+    Avoid interaction between multiple objects:
+
+    >>> bar = Foo()
+    >>> bar.answer
+    calculating answer...
+    42
+    >>> foo.answer__reset()
+    >>> bar.answer
+    42
     """
 
     def __init__(self, method):
@@ -27,8 +45,14 @@ class lazy_property(object):  # pylint: disable=invalid-name,too-few-public-meth
     def __get__(self, obj, cls=None):
         if obj is None:  # to fix issues with pydoc
             return None
+
+        def reset_function():
+            setattr(obj, self.__name__, self)
+            del obj.__dict__[self.__name__]  # force "__get__" being called
+
         result = self._method(obj)
         obj.__dict__[self.__name__] = result
+        obj.__dict__[self.__name__ + "__reset"] = reset_function
         return result