Cache uses WeakKeyDictionary

diofant · May 2, 2015 · 511090a · 511090a
1 parent a245180
commit 511090a
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/sympy/core/cache.py b/sympy/core/cache.py
@@ -1,6 +1,8 @@
 """ Caching facility for SymPy """
 from __future__ import print_function, division
 
+import weakref
+
 # TODO: refactor CACHE & friends into class?
 
 # global cache registry:
@@ -77,7 +79,7 @@ def __cacheit(func):
        set environment variable SYMPY_USE_CACHE to 'debug'
     """
 
-    func._cache_it_cache = func_cache_it_cache = {}
+    func._cache_it_cache = func_cache_it_cache = weakref.WeakKeyDictionary()
     CACHE.append((func, func_cache_it_cache))
 
     @wraps(func)