Issue 13227: Option to make the lru_cache() type specific (suggested by Andrew Koenig).
diff --git a/Lib/functools.py b/Lib/functools.py
index 038f284..1abb37a 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -121,12 +121,16 @@
_CacheInfo = namedtuple("CacheInfo", "hits misses maxsize currsize")
-def lru_cache(maxsize=100):
+def lru_cache(maxsize=100, typed=False):
"""Least-recently-used cache decorator.
If *maxsize* is set to None, the LRU features are disabled and the cache
can grow without bound.
+ If *typed* is True, arguments of different types will be cached separately.
+ For example, f(3.0) and f(3) will be treated as distinct calls with
+ distinct results.
+
Arguments to the cached function must be hashable.
View the cache statistics named tuple (hits, misses, maxsize, currsize) with
@@ -142,7 +146,7 @@
# to allow the implementation to change (including a possible C version).
def decorating_function(user_function,
- tuple=tuple, sorted=sorted, len=len, KeyError=KeyError):
+ *, tuple=tuple, sorted=sorted, map=map, len=len, type=type, KeyError=KeyError):
hits = misses = 0
kwd_mark = (object(),) # separates positional and keyword args
@@ -156,7 +160,12 @@
nonlocal hits, misses
key = args
if kwds:
- key += kwd_mark + tuple(sorted(kwds.items()))
+ sorted_items = tuple(sorted(kwds.items()))
+ key += kwd_mark + sorted_items
+ if typed:
+ key += tuple(map(type, args))
+ if kwds:
+ key += tuple(type(v) for k, v in sorted_items)
try:
result = cache[key]
hits += 1
@@ -177,7 +186,12 @@
nonlocal hits, misses
key = args
if kwds:
- key += kwd_mark + tuple(sorted(kwds.items()))
+ sorted_items = tuple(sorted(kwds.items()))
+ key += kwd_mark + sorted_items
+ if typed:
+ key += tuple(map(type, args))
+ if kwds:
+ key += tuple(type(v) for k, v in sorted_items)
with lock:
try:
result = cache[key]